CrimsonHyperSloth
Agreed. I hate K'nex, I found them the most frustrating and restrictive of the building toys.

Xenocide
Building toys in general are among the best things you can give a kid.

Billy the Poet
I remember Construx, Robotics, and Legos with great fondness. I also suspect I resembled glasses kid more than I want to admit.

Burnov
I had all of those when I was a kid, and I remember that commercial too.

Eventually I got the idea to make battle armor for the cat, that didn't go over so well.

And the cat's response to it was just to lay on the livingroom floor until I removed it.

Jane Error
I'm not sure why cats respond to foreign objects being put on them by not moving, but it seems to be their default defense.

For me, playing with Construx was formative for two reasons:
(1) I had my first encounter with gender stereotyping when a neighbourhood kid told me I wasn't supposed to play with them because I'm a girl (I did anyway--I loved and still love building things), and
(2) I realized that the "from Santa" sticker on the bottom of my Construx tube was written in my mother's hand. I immediately confronted her with the evidence and she told me not to tell my sister. My disappointment with there being no Santa was mitigated by the fact that I figured it out by being sleuthy.

gmol
I made a jetpack, and made my Dad take pictures of me jumping off a picnic table so it would look like I was flying.

It just looked like I was jumping off a picnic table.