...in a past life

people say often stuff like "oh that little girl has been here before" or "you must have been such-and-such in a past life" but to what extent do you believe that? i know there are those who believe in reincarnation but for some reason i was under the impression that you come back as something else every time like a butterfly. could you come back as human each time?

i'm pretty sure my client is having delusions, a symptom of his diagnosed illness, when he refers to events of a past life. but then how can i really know when people say stuff like that all the time? is it normal as long as you dont get too elaborate with it? are people just saying it in jest and it's only when you deeply and truly believe that certain things happened to you that you are "crazy"? plus for those who believe in reincarnation, do you actually know what you were when you were "here before"?

i really wanted to ask my client how he died each time (he'd been several different people) but i don't think we're supposed to go along with the delusions.