wasn't sure exactly what you were asking, so i tried to cover my bases with the answer.
regarding having enough belief for things to be possible, not to bash anothers views, but the reality is some things just aren't. belief can be a powerful thing, and while i applaud self discovery, you can't jump off your roof and fly if you believe hard enough, it's just not humanly possible. perhaps one day we could evolve to have the ability to see someones history in our mind like a movie, but right now, no. while i'm not as clairvoyante as others, from personal experience, it's feeling the energy in a room, an object, a person, not looking at someone and seeing in your minds eye how they murdered someone or whatever. that said, there are some psychics who claim they can see events, but not in that vivid of detail.