Here are some excerpts from Sal Khan’s 2012 commencement address at MIT. Go to Explore for an excellent post and the video of his remarks:
“Remember that real success is maximizing your internally derived happiness. It will not come from external status or money or praise. It will come from a feeling of contribution. A feeling that you are using your gifts in the best way possible.”
“…Start every morning with a smile — even a forced one — it will make you happier. Replace the words “I have to” with “I get to” in your vocabulary. Smile with your mouth, your eyes, your ears, your face, your body at every living thing you see. Be a source of energy and optimism. Surround yourself with people that make you better. Realize or even rationalize that the grass is truly greener on your side of the fence. Just the belief that it is becomes a self-fulfilling prophecy…
From 
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