I too used to get comics only at my local convenience store as that's the only type of place I knew that had them. A nearby town had a newsstand where you could also get them. I was about 5 or 6 years later I discovered comic shops. Then I got out of it for a while and just recently got back into it.
The situation with my son (he's 6) is sort of ironic in light of the Playstation and N64 comments here. It was the Playstation game 'Spider-Man' that caused my boy to take and interest in the comics!

He loves that damn game and then went nuts for Spidey so I pulled out my old comics. After that, he wanted more and then so did I. So I starting buying current issues and now we are having withdrawals to get the latest. (Of Ultimate SM and Team-Up...we both read that one, I've been reading ASM myself as the current storyline is just too advanced for a 6 year old I think.)
-Troy