Although I'm sure I camped before then, the earliest I remember was tent camping with my folks when I was 4, traveling by motorcycle in the SW. My dad was in the Air Force, so we moved around a lot and always traveled and camped wherever we were. Also pitched our tent all over Europe while stationed in Germany. When we couldn't find a campground we'd sleep in the back of the station wagon. When we came back to the states we got a big ugly green Chevy van and camped in that or pitched a tent. I'd always tent camped until I met my DH in my 30's.
DH's parents bought a pop-up when he was 10 and they always took that on their family vacations. He also slept in fox holes and tents while in the Army.
After we got together, the inlaws bought a 5-er and gave us the PUP. We've had the PUP for about 15 years (she's 40 now!) and just brought home our first ever TT. As we get older, we seem to like things easier. Getting up from an air mattress on the ground isn't as easy as it used to be! lol