My first experience was with a college coed who was a year younger than I was, and both were a little drunk. After dating for a summer, we were at college and she liked Arrow rum more than I did.
Though I came, it later became apparant that SHE wasn't as turned on as I was, having used a petroleum based hand cream to lube herself prior to coming to bed. As a result, the condom weakened and tore as I withdrew, and I panicked. What should have been a memorable, pleasant memory became a nightmare, as we feared a pregnancy and she admitted she had miscounted her cycle.
As a result, our relationship soured and she moved onto other guys "who wouldn't pressure me".
We just weren't on the same page, even though we thought we were that night.
Was it satisfying? Not nearly as much as when I had a regular partner and we grew together, comfortable that we could please each other and ourselves without risking pregnancy, disease or each other's feelings.
PS: We were both over age 21 by the time we started up regularly, and just about to finish college. Priorities.
Was this what you wanted?
I was 19 and had been dating my boyfriend for about a year. He was my first boyfriend and I loved him dearly; before him I had always thought that I was just going to live my life alone. Things got heated and it was not exactly a conscious thought. I was not as ready as I had thought and it hurt more than I would like to say; it took about a month to learn how to make it feel good, but as I had never done anything sexual before I just didn't know what to expect. I do not regret it per se, yet I do wish I had waited a little while until we got our own place instead of being fearful of roommate intervention and had worked a few things out. We were also stupid and didn't have birth control at the time, (thank god for the morning after pill). We talked a lot afterward about what would have happened if I had gotten pregnant and where our relationship was going. My main regret is that I didn't wait until after we married, especially since we are engaged two years later; it would have been sweet and special, even though I never had thought about it at the time. In summation to this rant, wait as long, or as short, as you would like, but make sure it is with someone special, that you are prepared, and talk about the consequences beforehand. Also realize that your feelings may change down the road.