The venerable master Qc Na was walking with his student, Anton. Hoping to prompt the master into a discussion, Anton said "Master, I have heard that objects are a very good thing - is this true?" Qc Na looked pityingly at his student and replied, "Foolish pupil - objects are merely a poor man's closures." Chastised, Anton took his leave from his master and returned to his cell, intent on studying closures. He carefully read the entire "Lambda: The Ultimate..." series of papers and its cousins, and implemented a small Scheme interpreter with a closure-based object system. He learned much, and looked forward to informing his master of his progress. On his next walk with Qc Na, Anton attempted to impress his master by saying "Master, I have diligently studied the matter, and now understand that objects are truly a poor man's closures." Qc Na responded by hitting Anton with his stick, saying "When will you learn? Closures are a poor man's object." At that moment, Anton became enlightened. -- Anton van Straaten (Na = Norman Adams, Qa = Christian Queinnec)

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?

A person won't retain proficiency at a task unless he or she has at one time learned to perform that task very rapidly. Learning research demonstrates that the skills of people who become accurate but not fast deteriorate much sooner than the skills of people who become both accurate and fast. -- Philip Greenspun

Only make new mistakes. -- Phil Dourado

Any fool can make the simple complex, only a smart person can make the complex simple. -- unknown

Premature optimization is the root of all evil (or at least most of it) in programming. -- Donald Knuth

Don’t be afraid to give up the good to go for the great. ~John D. Rockefeller

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

When you stop chasing the wrong things you give the right things a chance to catch you. ~Lolly Daskal

Remember that not getting what you want is sometimes a wonderful stroke of luck. –Dalai Lama