Nothing has ever really happened, since time travelers could go back and prevent everything that seemingly has happened from happening. They may have prevented themselves from coming into existence by the same process. A self-contradicting and hence impossible situation exists, a denial of all the laws of creation. This is a demonstration of the worst kind of logic possible. Speculations such as time travel are so devoid of rationality they fall into the category of insanity.
Insanity is a state of mind in which the individual is out of touch with reality.
The concept of time travel is a denial of reality. Therefore, a belief in this idea is by definition a form of insanity. This is actually another case of doublethink. All of the seemingly inexplicable occurrences which have been explained away by time travel, time warps, space warps, fourth dimensions and the like, can be simply and logically accounted for. Every detail of everything that has ever happened is recorded in the vast network of cosmic computers.