The detail you defend may need a clearer reason than the time you spent on it.

Effort quietly turns into justification. Once you have spent three days on a paragraph, a feature or a corner of a drawing, your attachment to it stops being about whether it serves the whole and becomes about what it cost you. That is a real feeling, and it is not an argument anyone else can be expected to accept.

When you find yourself defending something, try stating the case without mentioning the work involved. If the reason holds up on its own, defend it properly. If the only thing you can say is how long it took, that is usually the moment to let it go.