Having just one life serves no purpose for that matter.



"Common" sense is why you're in this mess.



You have no memories that is correct, but you have the most important thing carried over, character and attitude, beliefs, opinions, etc, etc. Memories of actual events aren't needed since those memories would be counter-productive.

You'd just end up being some sort of weird past life stalker.



Not quite, being female or male brings about their own unique experiences. Become too masculine or feminine though and you'll be gay in the next life to balance yourself out. Women wanting to be like men is never a good thing. As a whole though people tend to stay the same gender.




No real universal need for the sun to be billions of years old when you think about it. It is though.

Anyway you kinda get reincarnated because of the soul. That's the all powerful force that keeps people's spirits "locked up" in the flesh.



Even those who don't believe in that theory end up back here anyway. It doesn't matter what you "believe" in fact that tends to be one of the major reasons for most being here.



Wait until you are dead, and the time comes for you reincarnate here again. That's even harder to take, full in the knowledge that your memory of your past life, and your current personality is going to quickly vanish into that new baby body of yours (second death). You literally burst into the world crying.