You can absolutely dream about past lives. Children are especially good at it. I think that if you are drawn to a certain era, location, person, etc., people have concluded it's a possibility that your mind is taking you there for a reason.
Do your dreams parallel any part of history you feel drawn to, or even interests you. I am of the belief that coincidences are more rare in these cases than actual gut feeling.
I think reincarnated life keeps coming back just so that we finally are able to overcome are obstacles.
Anyway, many (if not all???) of the books I've read look to dreams as clues. I just wouldn't rule it out.
If you have any more specific questions, I would be interested in anyone here culd help.
