Pay attention to opportunity cost at all times. Doing one thing means not doing other things. This is a form of risk that is very easy to ignore, to your detriment. -- Marc Andreessen (http://blog.pmarca.com/)

Lisp programmers know the value of everything but the cost of nothing. -- Alan J. Perlis

Beware of bugs in the above code; I have only proved it correct, not tried it. -- Donald Knuth

Mastering isn’t a survival instinct; it’s an urge to excel. Mastering is one of the experiences that delineates us from animals. It is striving to be more tomorrow than we are today; to perfectly pitch the ball over home plate; to craft the perfect sentence in an article; to open the oven and feel the warm, richly-scented cloud telling you dinner is going to be absolutely extraordinary. We humans crave perfection, to be masters of our domain, to distinguish ourselves by sheer skill and prowess. -- Joesgoals.com

Actually, the essence of boredom is to be found in the obsessive search for novelty. Satisfaction lies in mindful repetition, the discovery of endless richness in subtle variations on familiar themes. -- George Leonard, Mastery.

Measure everything you can about the product, and you'll start seeing patterns. -- Max Levchin, PayPal founder, Talk at StartupSchool2007

Successful people do what unsuccessful people are not willing to doDon’t wish it were easier, wish you were better. ~Jim Rohn

Few things can help an individual more than to place responsibility on him, and to let him know that you trust him. –Booker T. Washington

If you can’t explain it simply, you don’t understand it well enough. ~Albert Einstein

An unexamined life is not worth living. –Socrates