Far better an approximate answer to the right question, which is often vague, than an exact answer to the wrong quesiton, which can always be made precise. Some models are useful. Computer science has such intimate relations with so many other subjects that it is hard to see it as a thing in itself. The true logic of this world is in the calculus of probabilities. Lately it doesn't seem to be working.
Opportunity is missed by most people because it is dressed in overalls and looks like work.
Nothing in the world can take the place of persistence. Persistence and determination alone are omnipotent. To succeed in the world it is not enough to be stupid, you must also be well-mannered. Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened. Sometimes I need what only you can provide - Your absence.