There's no feeling quite like that feeling you get when you return to a game you played eons ago (i.e. a few months) and remember nothing from your last save. I'm talking about the "what-button-do-I-press-to-attack" feeling you get as you watch your character get bitch-slapped by the last enemy you'd expect to kick your ass; the "where-the-hell-am-I-and-what-am-I-suppose-to-do" feeling as you wander the map mindlessly figuring out what your objective was; the "how-the-fuck-do-you-reload" as the sniper head-shoots you from 500 yards.
The fact is, it takes some time to get back into the game's "groove," and it's this precious length of time that many gamers don't want to spend again just to go back into a game that they dismissed a while ago. And with the constant flavor-of-the-month games that are released frequently, gamers don't have much time to thoroughly play and enjoy each game that drops in their lap.
It's important for a gamer to dedicate him- or herself to a game that they truly enjoy; to see it through to the end and give it the respect it deserves. Or, if the game was lost in the fray, to return to it on a timely basis and continue to make progress. I don't think I would have forgiven myself if I didn't finish Okami at all, or if I left Odin Sphere behind for something only half as good. On my plate now are Rogue Galaxy and Metroid Prime 2, with a little DS action on the side.
The only drawback? I don't start new games as immediately as their release dates.
That, and, ironically, I have to stop playing other games to dedicate myself to another.
It's a vicious cycle.