Sometimes an adult not under hypnosis may experience what seem to be memories of a past life.
Again, there may be rich details and sincere conviction. And again, almost always, these cases are easily subject to normal explanation and are scientifically of little or no value.
How can we know that the “memories of a past life” haven’t really been generated from this one? Nearly always, most likely they have.
A few exceptional cases are notable—for example, cases in which a person shows the ability to speak a foreign language he seems not to have normally learned. (This may also be a feature of cases hypnotically invoked.) Such cases are rare, and reincarnation is not the only possible explanation for them.