"Life is a sexually transmitted disease (which has a 100% mortality rate)."

(Ronald David Laing, Psychologist/Philosopher, 1927-1989)

P.S.: As far as I am aware only the first part of the quote is by Laing.
The second bit, i.e. "...which has a 100% mortality rate" has been added
by someone else. Sorry, don't know who added it.