A great quote I recently stumbled across but I need to keep reminding myself of:

“Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.”

—Brian Kernighan

Another fantastic quote attributed to Mr. Kernighan that applies to making most anything:

“Controlling complexity is the essence of computer programming.”

Many other useful insights here: Basics of the Unix Philosophy Scroll down to the rules and extend these beyond just Unix or programming.

Since this was all rooted in Unix, here’s a document I wish I’d read before first wading into the OS X terminal way back when: Learn UNIX in 10 minutes.