Wisdom is nothing more than confirmed imagination: just because one did not study for his exam does not mean that he should leave it blank.
He struck his temples with his fists and screamed: 'Haven't you ever seen a goddam DC converter? You can get them at Radio Shack for three bucks! Are you seriously trying to tell me you couldn't have made a simple DC converter when you can make your tractor fly and your typewriter run on telepathy? Are you?'Nobody thought of it!' she screamed suddenly.