I've learned that you can't have everything and do everything at the same time.

Take long walks in stormy weather or through deep snows in the fields and woods, if you would keep your spirits up. Deal with brute nature. Be cold and hungry and weary.

The whole problem with the world is that fools and fanatics are always so certain of themselves， and wiser people so full of doubts.

A company's core competitiveness lies not in how many resources it has, but in how efficiently it utilizes them.