We've all had those moments when we rip open the wrapping paper and discover that Santa didn't quite deliver the electronic wizardry we'd been nagging our parents for.
Whether we grew up in the 70s, 80s, 90s or noughties there have been wonderful, gadgety toys advertised for months before Christmas that just eluded us at the last minute. It might have been because it was sold out before your mum or dad got to the store. Or it might just have been too expensive.
Whatever the reason, you looked on jealously as the popular kid at school boasted loudly about getting what you wanted. We know, we feel your pain too.
So in a virtual group session of shared painful memories, here are a whole bunch of tech toys from the last 40 to 50 years that just slipped our grasp on Christmas morning.
The best news is that, as adults, you can track them down, buy them second hand or even new in some cases and covet them afresh as is the case with revived gadgets like the PlayStation Classic or Nintendo SNES Classic Mini.
Bigtrak (or Big Trak in the US) was a programmable vehicle that essentially taught kids to code many many years before it became popular. Released originally in 1979 but most popular in the early 80s, it had a keypad on the rear where you assigned different actions: go forward, turn left, that sort of thing.
A cargo trailer accessory was also released that clipped onto the back and delivered things, like a cup of tea to your dad. Mind you, considering how long it took to work out a complete programme of movements, no tea would ever get to its destination hot.
A remade model came out a few years ago, but didn't gain much traction.
We did get an Electronic Battleship for Christmas in the 80s but our nylon carpet created enough static to blow it up by Boxing Day. When our parents took it back it was all sold out and we had to have a skateboard instead. Disappointed isn't the word.
The game, which basically added bleeps and bloops to the traditional pen and paper or plastic and pegs version, was most notable for its cheesy TV advert: "You sank my battleship". And literally blew it up.
Nintendo Game Boy
We eventually got a Nintendo Game Boy but not for Christmas. It was the bees knees and changed the gaming market forever. Prior to the Game Boy, handhelds were effectively one-game affairs, but the swappable cartridges were quite literally a game changer. Choosing Tetris to come free with the machine was a masterstroke by Nintendo. We still have the music embedded in our brains. Decades later, Nintendo is at it again, this time with the Nintendo Switch, but sadly Tetris isn't included.
We could've included so many different Lego sets, including the Mindstorms range of technical kits, but this Monorail pack as part of the Space range in the late 80s is our biggest regret.
It sold like hotcakes, not least because it came with several minifigs, flashing lights, sounds and moved around the track on its own. It has now become a desirable collectable in its boxed form, which makes our missing out all the more painful.
Stylophone pocket organ
The Stylophone pocket organ was hugely popular in the 70s and 80s for almost no reason as it make a sound like an electronic cat being strangled. It consisted of a metal keyboard and stylus. When you ran the stylus over the keys, the contact between them barked out an annoying, almost offensive noise.
A recent entry this considering it was a massive hit last Christmas, the Star Wars BB-8 version of the app-controlled Sphero was incredibly popular. And as it was £130 a lot of children were very lucky indeed.
New features were even added to it at a later date, with some excellent augmented reality modes and the launch of a Force Band that can control the wee fella, so we'd imagine it still gets played with often.
Thunderbirds Tracy Island playset
The original Thunderbirds Tracy Island playset sold out so quickly that Blue Peter decided to show parents how to build their own, out of recycled rubbish lying around the home. However, even that was overwhelmed by requests for an instruction sheet on how to make it.
A new version of the Tracy Island set was released in 2000 but it doesn't have the same air of majesty as the early 90s predecessor.
Atari pretty much started the whole videogames console market in 1977 with the Atari 2600, or VCS as it was otherwise known. It was priced at $199 so around $830 in today's money, if you take inflation into account. Let's just say, if you got one of these for Christmas you were a very lucky child indeed.
The games were the equivalent of around $75 a pop, which was also a massive outlay, but it didn't stop company's like Activision forming to satisfy demand. The rubber joystick will also never be bettered we feel.
Star Wars X-Wing Starfighter drone
A brand new entry into our list purely because we think they will sell like hotcakes, the Star Wars drone series tick all the boxes for a must-have Christmas present that will unlikely be under kids' trees come 25 December.
It's £199 for a start and manufacturer Propel has crafted something very desirable indeed, especially the X-Wing Starfighter model. It even looks good when placed on its plinth and not actually flying.
Nintendo Game & Watch
Long before the Game Boy was a twinkle in Mr Nintendo's eye, the Japanese gaming giant tested the handheld water with its Game & Watch series.
Each device featured just one game with rudimentary controls and LCD graphics but they proved very popular indeed. A clamshell, two-screen version followed, featuring characters like Donkey Kong, which could even be seen as the forerunner to the DS.
Furby toys are still around and selling well, but the 1998 original was a massive sensation. It learned behaviour and spoke Furblish, which essentially meant it'd jibber jabber in the middle of the night and wake everyone up.
It's one of the tech toys that appealed to boys and girls and original models - with large, round eyes rather than digital displays - are still sought out by collectors.
Six Million Dollar Man action figure
Not technically a tech toy, the Six Million Dollar Man action figure kind-of fits this list thanks to the fact that he had hidden circuitry in his arm and a see-through, telescopic eye you could use to look at ants and stuff.
Based on the 1970s TV show of the same name, the plastic Steve Austin was seen as a more advanced Action Man so therefore we all wanted one. Sadly, the rubber sleeve that hid the circuitry was want to perish over time, so few pristine models are left.
Wii Balance Board
Considering how badly the Wii U sold it's easy to forget that the previous console, the Wii, was a huge hit - especially with families.
That's why Wii Fit and the Wii Balance Board sold in bucketloads, promising to make mums, dads and the sprogs more healthy through gaming. It was wireless and sensed contact, so different games used it for different activities. Like most fad toys though it ended up in the back of cupboards everywhere, alongside the Guitar Hero guitars and dance mats.
Sinclair ZX Spectrum
The Sinclair ZX Spectrum was a revelation on its release in 1982. It made home computing affordable and parents thought that by buying one for their kids, it would encourage them to do their homework. But it didn't really work, unless their homework consisted of playing Horace Goes Skiing for hours at a time and programming the computer to write "poo wee bum" thousands of times up the screen.
The original rubber keyboard model is the classic and most fondly remembered, but the Speccy went through a few iterations before Amstrad came along, bought the company and messed it all up.
Teksta (or Tekno as it is known in the States) is popular in its current form but first came to life in 2000 with a more robotic look and fewer features.
Still, it was advanced for its time and 40 million of them were sold in the first four years after release. It was so hard to get on its first Christmas that plenty of knock off versions were also popular. And it was reported at the time that parents were fighting each other in stores in order to nab rare stock.
Hypnotic and challenging, Simon was a simple electronic game but everyone seemed to have one. Except us.
You had to tap the colours in the sequence as they lit up, with the pattern increasing in number after each successful go. There was also a smaller travel version that you could sling in a bag and we genuinely think a rerelease would do as well today as it did back in the 80s.
Speak & Spell
Designed for younger kids, Speak & Spell had an allure for older children too, thanks to its hangman game and different difficulty levels.
It was one of several Texas Instrument electronic devices that were designed to make learning fun. There also weren't that many speaking toys back in the late 70s, when it launched. A true novelty and a classic.
Lazer Tag is still available today, in several more modern guises, but you can't beat the 80s original.
Kids slipped on a vest with an infra-red sensor on the front and armed themselves with IR blasters. The vests kept score and you were out if you were hit too often. It seemed so fresh and advanced when it first arrived. Now just feels like mucking around with a couple of remote controls.
Total Control Racing
Total Control Racing (TCR) was the cooler rival to Scalextric that ultimately fell by the wayside. That's mainly because, unlike its peer, the magnetic track that allowed cars to switch lanes also meant that it was hard to actually spin off so races were nowhere near as perilous.
That also meant it wasn't as much fun. Still, it was always a playground topic on who had Scalextric or TCR and the latter kids usually commanded the most respect.
Galaxy Invader 1000
Like the Game & Watch, handheld machines were one-game affairs back in the 80s and one of the very best was Galaxy Invader 1000.
It offered a limited but fiendish Space Invaders-style game with aliens coming down one of three lanes on screen and you had to wobble around a small stick to control your fighter craft to stop them.
It guzzled batteries, but was well worth it.
Tomy's Omnibot, which lasted a few generations before being discontinued, was much like the Bigtrak in the 80s. It could be programmed to go where you wanted and essentially encouraged coding practices.
However, Omnibot also had a few extras up its metal sleeves. For a start, there was a cassette player in its chest so you could break dance along to its own slow movements.
Anki Overdrive is the more recent version of this app-controlled AI racing game, but Drive is where it all started. It was also a massive success a few Christmases ago, much to even Anki's surprise and delight.
The cars have brains of their own, so can stick to the vinyl track well, but it's the phone application that makes a game of the proceedings that is the clever part. The only drawback is that it's a pricey present for a teenager.
NES Classic Mini
When 2016's NES Classic Mini came out it was a huge success - so much so that it was almost impossible for those who didn't pre-order one to get it. The recreated Nintendo Entertainment System was reasonably priced, with 30 pre-installed games for your £50, so sold out quickly.
Thankfully, if you still feel like dabbling with a spot of early 80s gaming you can now get one as more stock was made eventually.