I know a lot of us have beaten a lot of games, but how many have you actually completed (aka you've done everything the game has to offer, gotten everything, used everything, every way, every ending, etc.)? It's a not something people do regularly. People beat games, but they don't do everything.
Earlier this morning I COMPLETED Burnout Paradise, aka 100% in-game status (I still have to do all the online challenges, though), and I really felt proud that I did everything the game asked me to do. The last time I felt this way was when I completed Super Mario Galaxy (Yes, all 242 Stars), and that was the last game I got 100% on as well. And yes, I even got the special 9999 Star Bits Watermelon re-skin for Mario and Luigi.
I mean, sure, you can say I got all the Achievements or Trophies in Halo 3, or Prince of Persia, or LittleBigPlanet, but Achievements/Trophies aren't something that truly make you satisfied when you "Complete" a game. Getting 1000g doesn't mean you completed every side quest. Getting a Platinum doesn't mean you took an alternate path to get some worthless easter egg. It's just an arbitrary thing that doesn't mean anything. Completing a game is truly something special that shouldn't be taken lightly, and if you compelte a game, you know what I'm talking about.
It's different. It's not something 1000g or a Platinum Trophy can touch, or even grasp.