Do you believe in past lives?

I'm reading a book about uncovering your past lives. This doctor (?) claims he can counsel his clients and help them to remember their past lives through their chronic pain(s) and fear(s).

For example, one client has a crippling fear of tunnels and tight spaces. While he's driving through a tunnel, he begins to hyperventilate and fears he will die. Through this interesting counseling process, he uncovers that in a past life he died in a mine cave. His last moments in his past life, he gasped for air and suffocated in a tight space.

Another client suffers from pain on the left side of his abdomen. He recalls feeling the pain as a child after running too hard. Eventually, he uncovers in a past life, he had suffered from a bad injury while falling off a horse and being punctured on the left side of his abdomen when he fell.

I'm still quite skeptical but very interested in learning what others believe. So, what do you think? Do you believe you lived before? Do you believe you'll live another life after this one?