The importance of output

This is old story in my life, my senior in my previous laboratory who dropped out said me at his graduation, "I wanted to be more smart so I read many books, I never lose the number of books I read. However, I found I had been senseless. The important point is not the input but the output. Finally I understood it at around three months prior to graduation time. I was failed but I found, so I don't want you to make the same mistake."

I don't remember the detail but almost it's correct. Honestly I didn't respect him at all but those words impressed me a lot at that time. If I feel distress about output, I used to remember his words. In other words, recently it's hard to write this blog because of idealess.