Anyway, if we believe all this to be what happens when we die then there is a scientific hypothesis we can make that must be absolutely true.
Ghosts can not masturbate.
It's widely accepted that the best thing about being a ghost is seeing people naked that you never could when you were alive. At first this seems like a brilliant thing to hang around for, but let's face it, after 4 or 5 years of naked, it would start to get old.
Now if you could experience this forbidden nudity while retaining the self pleasuring skills you had while living, there would really be no reason to follow that light into heaven. In fact if jerking off was possible in the astral plane Heaven would be a place on Earth, which would make Belinda Carlisle some kind of Nostradamus like figure.
There would be a very small crowd in Heaven and the people who were there would walk around wondering when everyone else is going to show up, much like the time I went to that Air Supply reunion concert. Then when word got out on the shenanigans happening on Earth, they would all feel like idiots and wish they had stayed home and masturbated all over the place, much like the time I went to that Air Supply reunion concert.
The point is, the whole afterlife system would fall apart if ghosts could jerk off, not to mention the overcrowding that would be going on in the bedroom of my 7th grade Social Studies teacher. It would be a disturbing world drenched in shame and ectoplasm. The universe would be thrown into chaos.
So you can stop wondering now. Enjoy it while you can.