[Discussion] Why do you go for platinums?

I stream going after platinums. And nearly every single regular viewer I have that goes after platinums has a different reason for doing so. I go after platinums because I feel that I've seen everything a game has to offer once I've got that final trophy. It gives me a feeling of completion that's tangible, and lets me put aside the game with the knowledge that I can make an informed opinion about it now that I've seen everything. What's your reason?