Apparently, those really smart people aren't familiar with the law of the conservation of energy. Our energy, or soul, etc. has to go somewhere...
I've definitely wondered about it, and read up on pretty much any idea out there on it. It is intriguing. I keep coming back to REALLY GOOD cases of reincarnation, where it's just too damn obvious that yeah, that person seems to remember an awful lot about a past life they couldn't have otherwise known about. So it certainly points to SOMETHING after....
Personally, I feel we kind of travel, as only energy can, to a different plane/universe, etc. of existence...one that can even interact with our own, in certain ways, but also following rules we don't yet know. Some of us, likely most of us, simply kind of melt back into a collective universal consciousness, but others, who've maybe lived more lives on Earth (or elsewhere), etc. may retain more individual signatures, and then choose to come back, reborn into another body, while other bodies simply pull from the collective for their "soulstuff"....
Again, just my own imaginings on it, based on different phenomena from things like past life cases, spirit communications with entities, etc. It could all be hogwash, for all I know, but since actually doing astral travel, and seeing the stupid silver cord (which I used to always think was bs)....it's made me realize that there may be a lot more to it all, and that maybe we aren't as ignorant about it as we think we are.
That all said, the below is definitely some good, solid advice: