Little kids are that way; they feel if their parents aren't watching what they do then what they do isn't real.
Philip K. DickThe pre-Socratic Greek philosopher Parmenides taught that the only things that are real are things which never change... and the pre-Socratic Greek philosopher Heraclitus taught that everything changes. If you superimpose their two views, you get this result: Nothing is real.
Philip K. DickYou're - psychotic. There's something wrong with you." "I know," Benteley agreed. "I'm a sick man. And the more I see, the sicker I get. I'm so sick I think everybody else is sick and I'm the only healthy person. That's pretty bad off, isn't it?
Philip K. DickWell, I hate to admit it, but it is possible that there is (one) such a thing as telepathy and (two) that the CETI project's idea that we might communicate with extraterrestrial beings via telepathy is possibly a reasonable idea--if telepathy exists and if ETIs exist. Otherwise we are trying to communicate with someone who doesn't exist with a system which doesn't work.
Philip K. Dick