The Pragmatic Programmer

If you’re brought into a project where people are desperately struggling to make changes, and where every change seems to cause four other things to go wrong, remember the nightmare with the helicopter. The project probably is not orthogonally designed and coded. It’s time to refactor.
And, if you’re a helicopter pilot, don’t eat the fish

The key to solving puzzles is both to recognize the constraints placed on you and to recognize the degrees of freedom you do have, for in those you’ll find your solution. This is why some puzzles are so effective; you may dismiss potential solutions too readily.

The tester selected the brush tool and painted a stroke from the upper right corner to the lower left corner. The application exploded. "Oh," said the programmer, in a small voice