I'm 21, and I go through phases, since coming to uni and becoming friends with people who are really into games, I've definitely started gaming more than I used to, and have made great friends through it as a result
However for most games I'm still very temperamental, in that I'll play a game loads, almost obsessively for a while, then won't play it for ages, then will come back to it eventually (maybe) kinda thing.
Only game that breaks that trend is TF2, which I've really got into, and is the main game I play now.
In the end, I wouldn't worry, just try other things and who knows, you might come back to gaming sooner rather than later, either playing an older game or finding a new one which tickles your fancy