Reincarnation

I've always wondered what's the deal with the religions where people reincarnate all the time. I can see how you can get some people to believe in heaven or hell or being reborn at the end of the world as we know it, but isn't it empirically self-evident that we did not have a previous life?

I suppose that the standard answer would be that the part of the soul that reincarnated is too small or too lofty to contain memories and/or personality of the previous host, but doesn't this render the whole concept of reincarnation rather meaningless?