Ecclesiastes 11:9
              Rejoice, O young man, in thy youth; and let thy heart cheer thee in the days of thy youth, and walk in the ways of thine heart, and in the sight of thine eyes: but know thou, that for all these things God will bring thee into judgment. 
           
                
              Ecclesiastes 12:12
              And further, by these, my son, be admonished: of making many books there is no end; and much study is a weariness of the flesh.