In Pokemon Platinum, my game starts off as if I've already battled everyone, help?

This could either be a weird glitch in your game, so your game might be corrupted. Or it didn't save right. If you remember it saving right, and you didn't go battle anyone in the survival area yesterday, it is probably a glitch. If this keeps happening, the saved file you have could disappear. Check the DS game slot for dust and dirt and the DS game. If nothings wrong with that, your game is just messed up. The only way I know of now to do is get a new game. But, I'll try and check back for other ways if I find any. Hope this helps at all.