The first time I smoked was when I was 15 and it was a SHITTY joint. Me and two people I knew, who up to that point were nerdy type people, decided to start smoking pot, and we didn't know what the hell we were doing. I remember the second time I smoked was with a long time stoner, and we were using a pipe, he kind of critiqued me on my inhaling method. A few days after that, deciding that pot didn't work on me because I hadn't gotten high, I ended rolling a joint about as big as you can without it falling apart. I remember smoking it outside, and towards the end of the joint, I started getting this fuzzy feeling. And sure enough, ten minutes later I was laying down in awe, because before I got high, I thought pot would just be subtle effects.
My first time I smoked a bowl with a few friends. We took a guy's car (I still don't know who he was) and drove around the country, smoking. I was pretty young (not old enough to have my driver's license and be on a loose leash yet), can't remember exactly how old, so I had to be home pretty early. I didn't smoke a ton. I got high, but not high enough that I realised it. I thought it had done nothing until the next day when I was talking to my friend and describing what had happened the day before. Then I realised I'd been high.