And sometimes the reality is that the realistic answer to a time estimate is "If we are lucky it takes me 30 minutes, if we are unlucky 30 days". E.g. when it

And sometimes the reality is that the realistic answer to a time estimate is "If we are lucky it takes me 30 minutes, if we are unlucky 30 days". E.g. when it turns out to your surprise, that a part you had in your hardware design was replaced with a part that was 5 cents cheaper, but uses a undocumented protocol that someone has to re-implement, so a goal that was trivial in theory has suddenly involves hardcore reverse-engineering in a high pressure environment. A thing all engineers love. The only time someone can give you reasonably accurate estimates is when they do something that down to the tiniest detail they have done before. The problem with that is, that in software things change constantly. A thing that was trivial to do with library X and Component Y of version 0.9 might be a total pain in the rear with Library Z and Component Y of version 1.0. But yeah, unexperienced engineers are going to be optimistic that it is possible, because in theory it should be trivial.