once when i was 17, i was intoxicated on marijuana that i accepted to eat a few hours before, and i was driving over the sydney harbour bridge, and i suddenly became freaked out.
i realized that no other consciousness in the universe saw the universe from my exact perspective.
i realized that no one's eyes were in the same place looking at the same things as my eyes.
therefore i realized that no part of the entirity of my whole internal experience has ever been, or will ever be experienced by anyone else.
that was a chilling realization, and i thought i was going insane, so i had to get the car across the bridge, and into a side street where i could park and think, and the chore of doing that seemed insurmountable. i felt very disoriented by what i had just realized, and i had to adopt a "tunnel" vision approach to getting the car off the freeway.
i felt as if i was going to go insane completely in a short while, and i eventually got off the freeway and parked, and i thought...,
and i thought....
after a while, even though i could not "understand" my way out of my sudden philosophical predicament , i was starting to feel confident that i could make it home if i waited a few minutes.
in the mean time (and earlier), i had gotten out of my car, and i was wandering around aimlessly, and when i finally decided "yes i can do it", i realized i had no idea where the car was, and i could not find it.
there was luckily a train station (milson's point) near by and so i went home by train and taxi, and the next day i woke up refreshed and i knew exactly where the car was, so i caught a cab directly there, and i drove home.
i never really resolved my original philosophical dilemma, but my concern about it healed rapidly.