I can never deal with the specifics as far as my own experiences are concerned. It's always a feeling to me, never a very clear visual or audial or any kind of "tangible" lucid experience. I "feel" as though I was "born" with certain aspects of my person that, since my childhood, I have never been able to understand how they could come from my particular surroundings in "this life." I've always had an analytical, questioning mind and I like to think I have the "nature vs. nuture" part of my life figured out. Certain aspects of my nature just don't attach themselves to anything in my past I can think of, certainly they're not parts of my mind that can be psychologically attributed to growing up in my generation, in my town, with my reactions to family friends and my entire life. I came into the world with some issues, and whether it was a past "life" or not, however you want to define these kind of things, it gives me reason to draw certain conclusions about who I might have been. Add a little bit of lucid dreaming, meditation, and psychotropic drugs, and I've had a few weird experiences. During one acid trip I felt as though I entered a transitive period in time, and my friends and I were living an archetype of the "town fools" in greco-roman times, and from some other time period I couldn't be certain of, as well as the present time. We weren't wearing tinfoil hats but we were a spectacle walking down the street in rain ponchos, tripped out and staring at the sky.
So I guess thats why I believe it, at the very least.