I have heard the first verse of the following quote too many times to remember. What I do remember, is that a lot of those times, people who repeated these words weren't even aware of who they were quoting. Today I give you the words borrowed from the greatest bard in history of literature, William Shakespeare (Hamlet):
"This above all: to thine own self be true,
And it must follow, as the night the day,
Thou canst not then be false to any man."