Shakespeare Said it Best

"Give thy thoughts no tongue, nor any unproportioned thought his act.  Be thou familiar, but by no means vulgar.  The friends thou hast, and their adoption tried, grapple them to thy soul with hoops of steel; but do not dull thy palm with entertainment of each new-hatched, unfledged comrade.  Beware of entrance to a quarrel: but, being in, bear't that the opposed may beware of thee.  Give every man thine ear, but few thy voice:  Take each man's censure, but reserve thy judgment.  Costly thy habit as thy purse can buy, but not expressed in fancy; rich, not gaudy: for the apparel oft proclaims the man;...neither a borrower or a lender be: for loan oft loses both itself and friend, and borrowing dulls the edge of husbandry.  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."

-Polonius in Hamlet

Fantastic advice from not as fantastic of a character in the play. We're reading the play and watching the 1996 version of the movie in my History of Creativity class.