Although maybe not entirely fitting into the “Geeky” category, i think it deserves a mention anyways,
When I was 11 years old, my christmas present was a SNES and The Legend Of Zelda. Now my parents didnt know i knew about Santa, and they kept on playing on about will he or wont he bring something nice this year..
But sneeky little me knew not only that Santa wasnt real (sorry to all those believers) but that I also knew where they had hidden the presents.
So one afternoon, i went up into the attic with a bag and opened the Snes box and dumped the console and Zelda into my school bag. I then snuck out of the house and ran over to my friends house who lived a few doors down. His big sister was minding him so she had no idea! :O We sat and played Zelda for about 6 hours straight. And if that wsant good enough, i did it again a few days later.
To this day i dont think they know, so i really hope they dont take an interest in game development.. Also i had to put on some act on christmas morning, faking my excitement. Il never forget it!