Everyone thinks they understand what they are implementing but then inevitably encounter some unexpected "feature". Tests help, but yeah... halting problem. As

Everyone thinks they understand what they are implementing but then inevitably encounter some unexpected "feature". Tests help, but yeah... halting problem. As for those great programmers how many sloc can they write without any compilation error and have the application executing as intended? If they make mistakes then bugs can also happen. It's only a matter of code complexity.