If it compiles, then it's correct.

Don't get me started on this one! I got so angry in school where we'd have test on computers and the guy next to me complained that he got a "B" because his program compiled, never mind it didn't do what the assignment said. Meanwhile we'd get these written tests where we'd have to write the code down by hand. I got downgraded to a "B" because I left off a few semicolons, never mind that I had the logic right.