When I was a wee boy, the abundance of G1 characters startled me, but it was good fun after the first 10 minutes.
I don't at all remember when I first heard of Transformers. I was born after G1 took off, so TFs were a staple toy then. Same with things like LEGOs and Batman; they were just always there...
I recall first seeing them in Minicon form. My brother got these three military minicons with these big-ass projectiles, and I was jealous because I got this Beetlemon action figure with a display case. My uncle felt sorry and went out to buy me an Armada Hot Shot. I still remember flipping out the axle cannon to send my bros minicons flying. Then my collecting died out when Energon started... Until I saw the TF1 trailer that played before Night in the Museum.
I always wondered if cars,planes and such were robots, then I saw my first TF back when G1 had just come out in the states and i was awe-struck. LOVED THEM!