This advice will go a long way towards happiness. It isn’t an excuse to be selfish or uncaring of others but to find who you are and what you want to be. A path we’re all on.
“Be yourself- not your idea of what you think somebody else’s idea of yourself should be.”
-Henry David Thoreau
Preindustrial Craftsmanship 
Great minds work alike, Wm. Shakesperre said ” unto thine own self be true”.
Great advice, and from others before them.
“Be yourself, everybody else is taken.” – Oscar Wilde
I wonder which contemporaries we will quote in 100 years…