One good way to tell if you are insane is to count the conspiracy theories that you believe in.

http://www.skeptics.org.uk/article.php?dir=articles&article=what_are_conspiracy_theories.php

In my own scale, there are several levels of belief, each of which corresponds to a level of mental stability or instability.

If you believe in 0-3 conspiracy theories, you are in the realm of normalcy.

If you believe in 4-8 conspiracy theories, you are in the somewhat eccentric.

If you believe in 8-12 conspiracy theories, you are losing it, so seek mental health care immediately.

If you believe in 13-16 (or more) conspiracy theories, you are totally insane. Don't bother to seek mental health care professionals since all psychiatrists and psychologists are part of the great conspiracy. In any case, THEY will find you no matter where you hide.

http://en.wikipedia.org/wiki/Conspiracy_theory

http://en.wikipedia.org/wiki/List_of_conspiracy_theories

David F Mayer