Russell H. Conwell 
Every Man is Own University [EPUB ebook] 

A distinct university walks about under each man’s hat. The only man who achieves success in the other universities of the world, and in the larger university of life, is the man who has first taken his graduate course and his post-graduate course in the university under his hat. There observation furnishes a daily change in the curriculum. Books are not the original sources of power, but observation, which may bring to us all wide experience, deep thinking, fine feeling, and the power to act for oneself, is the very dynamo of power.