As a prayer minister, I have ministered to people who had stories of a past life. They assumed they had a past life and reincarnated into their present body. They generally didn't think much of Christianity, which assumes there isn't any reincarnation.
Both of them are wrong. The Christians are wrong that there isn't reincarnation and these troubled people are wrong that their soul was "born again" into another body.
The troubled people can be hosting demons that they got from occult activities or their parent's occult activities. These demons are thousands of years old and have infested countless humans, watching these previous humans doing and experiencing things. The demons still know what they did.
The troubled people may have psychoses, trying to have a new identity because their real identity was just too painful. They usually have dog-eared books & worn out tapes of the person they wish they had been. They adopt these accounts, including the false information in these records. "I remember chopping down the cherry tree and telling my father I did it," says "George Washington."
For the first person, deliverance gets rid of the demon that has been the source of information. For the second person, they need healing of the traumas of their childhood, so they can accept their real self. Only we Christians can do both of these things.
edited: April 09, 2015 orderofsaintpatrick.org/real-reincarnation.htm