I bought my own Scremin' Serpent Roller Coaster kit after selling hundreds of them online one Christmas as an affiliate (and making a nice commission). I loved roller coaster and though it would be neat to sell the kits on my Disneyland/roller coaster website - turned out to be one of the toys of the year that Christmas!
I also bought a Trampoline Tower, Which I loved to modify, and then kinda fitted them together and put Christmas lights over it. A large picture of myself on Disneyland's Gadgets Go Coaster is in the background.
I curtained off the K'nex so you couldn't see it and invited all the family over for a 'grand opening party' (I had some young cousins who might be interested) and then with lights out, and the music of Disneyland's Main Street Electrical Parade, I opened the curtain and started both up when the main theme of the story started. I have footage of this somewhere..... somewhere....
Later I 'rented' out the roller coaster and Trampoline Tower as a fund-raising effort but the Trampoline Tower was never returned.
This bugged me for ages but now some 20 years on, now with a daughter of my own, I've gotten back into K'nex and have more than I need... or do I.... Yeah!.... (nah!)
And that is how I got started into Knex.