Kernighan's Law: You are not smart enough to debug it
I've always found this one a bit peculiar - usually debugging is about looking at something on a simpler, lower level than implementation. Rather than looking at a whole set of logic, let's step through it piece by piece, look at each operation. When done slowly with care and understanding of the lower level components in the system, debugging code is simpler than learning and implementing most architectural patterns in all but the most extreme of circumstances (compiler bugs, hardware faults).Or maybe I just spent too much time in OllyDbg at a young age to notice.