My grandfather was truck driver. He knew his truck as his fingers. He could reassemble drive of his car at weekends. If he wouldn't possess skills to repair his

My grandfather was truck driver. He knew his truck as his fingers. He could reassemble drive of his car at weekends. If he wouldn't possess skills to repair his truck, he would die somewhere on the winter road when that truck breaks, so it's not even question of preference, it's question of survivability. It's not as drastic for programmers, but I, personally, trying to keep that attitude myself and I'm trying to learn systems I'm using to some degree.