The most effective debugging tool is still careful thought, coupled with judiciously placed print statements. - Brian Kernighan

Controlling complexity is the essence of computer programming.

Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?

Associative arrays are very very useful things and if you are only going to have one data structure that's the one to have. Because you could build everything else with it if you want.