Narrowness of experience leads to narrowness of imagination
There's no such thing as a simple cache bug.
A smart terminal is not a smartass terminal, but rather a terminal you can educate.
Fancy algorithms are slow when N is small, and N is usually small.
Data dominates. If you've chosen the right data structures and organized things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming.
Rule 1. You can't tell where a program is going to spend its time. Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is