If I were playing chess in the park and Gary Kasporov walks by, sees a move that I'm about to make and says "that's a mistake, I'd recommend against that", then I'd be an idiot not to strongly reconsider my move, whether he explains himself or not. Sure, he makes mistakes, but Kasparov is an unimaginably better at chess than me and the chances that I make a mistake and don't see something that he does are much much greater. With chess though, it's hard to overate yourself because you can see exactly where you stand. With software engineering though, it's very easy to overestimate your abilities.