Ernest Hemingway - How little we know of what there is to know....

How little we know of what there is to know. I wish that I were going to live a long time instead of going to die today because I have learned much about life in these four days; more, I think than in all other time. I'd like to be an old man to really know. I wonder if you keep on learning or if there is only a certain amount each man can understand. I thought I knew so many things that I know nothing of. I wish there was more time.