In general, we can think of data as defined by some collection of selectors and constructors, together with specified conditions that these procedures must fulfill in order to be a valid representation. -- SICP, What is meant by data?

Acknowledging the negative doesn't mean sniveling [whining, complaining]; it means facing the truth and then moving on. -- George Leonard, Mastery.

In theory, there’s no difference between theory and practice. But in practice, there is. -- Albert Einstein

Il y a très loin de la velléité à la volnt, de la volonté à la résolution, de la résolution au choix des moyens, du choix ds moyens à lapplication. -- Jean-François Paul de Gondi de Retz

It’s a problem if the design doesn’t let you add features at a later date. If you have to redo a program, the hours you spend can cause you to lose your competitive edge. A flexible program demonstrates the difference between a good designer and someone who is just getting a piece of code out. -- Gary Kildall (inventor of CP/M, one of the first OS for the micro).

Whatever is worth doing at all, is worth doing well. -- Earl of Chesterfield

Every strike brings me closer to the next home run. –Babe Ruth

I find that when you have a real interest in life and a curious life, that sleep is not the most important thing. ~Martha Stewart

The only place where success comes before work is in the dictionary. ~Vidal Sassoon

Success is walking from failure to failure with no loss of enthusiasm. ~Winston Churchill