"Programmers need at least a small dose of humility and, at the same time, a bit of assertiveness. Without humility, the programmer will become overconfident which eventually leads to over-reaching and self-destruction.
… Assertiveness and humility moderate each in a programmer’s personality. Weinberg likens assertiveness to a steam boiler and humility to a safety valve. Without the boiler, no work gets done; without the safety valve, there’s real danger of an explosion."