What's the Best Mind Fuck? (Story/idea that is amazing to think about)

[Diphenhydramine]

For those not in the know, a "mind fuck" is a theory or story or idea
that thinking about it is amazing. A classic mind fuck is the
concept of an everlasting universe, where our entire universe is just
some atom in another person's universe, which is an atom in another
person's universe, and so forth, continually repeating.



One I thought of is the concept of deja vu. Recent studies say
that deja vu is when we interpret an image into our long term memory by
accident instead of in our short term memory. Because it is
processed in the long term memory, we automatically think it is
something we have seen before, hence deja vu. The mind fuck I
thought of is what if our entire day, week, month or even life was a
deja vu? That perhaps we are actually a child right now,
believing that we are a teenager or adult, or that we are even a baby
in a womb?????



Please list some more. Mind fucks are awesome to think of when you're high.