this is what really happened, to clarify the questions for you guys. when you turn on your ps3, you make a profile. for instance, i have mine and my brothers on there. also, you have the name you log onto the psn network with. i had this name when i first bought my ps3 (it was one of the first gen ones, before they even had trophies), and i didnt even use it for years since i couldnt play online. recently, about 2 months ago i turned it on and got my psn name going, and i started getting trophies, but i had beat a whole bunch of games on my system and hadnt gotten any trophies for them.
so for instance, i had 50 cent, blood in the sand (lmao yeah i know…) beaten all the way through with everything unlocked, and when i played through the campaign for a little while i didnt get any trophies. so in conclusion, the only way to get those trophies is to beat the game over again after you delete your save file.