Though millions of people believe in reincarnation, very few actually claim to have memories of past lives. Usually such recollections emerge during a controversial (and largely discredited) psychotherapy technique called "past life regression." In fact, that's how the "best case" for reincarnation came about.

While scientists cannot say with 100% certainty what happens after we die, by now, there is a significant body of evidence that suggests that reincarnation and rebirth are real phenomena. And, as with any scientific theory, the more evidence that supports it, the more probable it becomes.