[TillE]

This is probably the most important point I remember from "The Demon-Haunted World", in which Carl Sagan repeatedly demonstrates that human memory is completely unreliable, and that false memories can even be accidentally created by a therapist. People who say they've been abducted by aliens usually aren't lying; they genuinely believe it.

[mjklin]

The book Mistakes Were Made (But Not by Me) by Tavris and Aronson delves into this in great detail. Well worth a read.