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.
Act 1, Scene 3, line 78-80.
Said by Polonius to Laertes this advice may seem trivial and snobbish while taken out of the context, but these words become highly ironic when we take into consideration the personality of Polonius. He is a liar, a treacherous, deceiving man. We see here just how much of a hypocrite he is, giving the advice about being true and not being “false to any man”. Even when telling this, Polonius continues scheming, not putting any meaning and sincerity to his words. He plays the role of a wise mentor and his play is quite shallow.
This quote adds even more contrast to Hamlet, who never speaks with cliches, using the clever and creative metaphors and continues to explore his own thoughts, feelings and soul. Hamlet is anyone but a shallow person. He can be rough, but he indeed is an embodiment of the advice given by Polonius.