As most people have already said, its a common transition in all gamers lives. Even though some of us say otherwise, most of us aren't 40 year old virgins who still live at home with mom and dad. We all take whatever time we can out of our lives, and spend it on what we love to do. Whether its model airplanes, or remote control cars, just being able to continue the hobby, is a reward in and of itself.
Trust me, I've been that guy who plays video games for entire days, and I'm sure just about everyone on here has been as well. Thats the wonder of being a kid, being young. No responsibilities. Its a wonder we ever managed to even do our homework back then. I've slowly made the transition over to what is known as the "Casual" gamer(even though I hate that term). I used to be able to dedicate hours upon hours into games like Banjo-Kazooie or Super Mario 64, just to 100% them. Nowadays, I find other ways to whet my gaming appetite. I play CS:S, I play TF2, I play handheld games, and I roam these boards in whatever spare time I have. I still enjoy games the same way, and I'll indulge myself every once in a while on a massive time dump (RPG's and whatnot), but my love for games has never faded.
While it certainly is disheartening to look back and say that you wish you could be back in the good old days, you have to realize that you're love for gaming is still the same. Its just how you enjoy gaming, is different.