I do believe that very few of them have a real power to see things the others are just pretending.
You just need to tell psychic what specifically you want to know and leave other stuff unspoken. It is really hard to live when you know some thing that will/will not happen in your future.
I would not bother with the past at all, only of you have to . You can't change your past but you can change the way it affects your future. Be careful there.