I strongly disagree. Every programmer must be confident about their code. I code and I can explain how each and every line work, and I organise it to be simple

I strongly disagree. Every programmer must be confident about their code. I code and I can explain how each and every line work, and I organise it to be simple and side effect free. This helped me produce literally maintenance free software for so long. This only comes from the confidence of saying "I know exactly what my code does!". People who doubt their code or design usually end up bad programmers as they are not sure what their code does and it's side effects and they constantly seek other's opinion in the name of 'better implementations' - but there is no right design in reality, all one can do is produce small, concise, to-the-point side effect free functions that does solve one and only one problem at a time.