I am loving this discussion... keep it going!
For me, I remember picking up packs of cards when I played little league in the late 70s. After each game we would all get a ticket that we could use for any single item in the snack bar. Most kids would get candy but my friends and I would pick up packs of baseball cards. We'd sit on a rock and rip open the packs looking for Yankees, which were the only cards that mattered to us then. I'd take the cards home and keep them in a little metal box that I had on the floor of my closet.
I didn't get serious about collecting until 1986. My grandmother took my cousin and I to a retail supply store and picked up two of the boxes of wax packs, one for each of us. We spent the rest of that day opening packs, comparing and trading to build that set. That was the same year my dad started taking me to baseball card shows to see if we could find dealers selling commons to complete that set. As a side bonus, the shows my dad took me too always had players signing so we started picking up signed balls at each show... Mantel, Dimagio, Pete Rose, Billy Marttin, etc and my dad would snap a picture of each as I handed them the ball to sign. Been hooked ever since and now my son and I go to card shows and go to Cooperstown every year to pick up a couple new signed balls. We're up over 70 hall of famers and several others who aren't in the hall. Even my daughter started getting into the hobby this year looking at Pokemon and other odd ball cards (she's not a sports fan) but she's enjoying card shows and wants to go when they come up. (side note, if anyone has pokemon cards, hit me up and I'll see if she wants them for something I can trade back from my cards)