Premature optimization

Premature optimistic comes from the idea that you must have things perfect before you can start using them.

It is like the idea that you can't go through a narrow path but that before you go anywhere you need building a highway with multiple tracks and everything else.

It is usually something people use to procrastinate, delaying useful work because the font is not perfect, images on drafts aren't pixel perfectly aligned, the wording is not perfect from the start, etc.

First build, test it, and later — if required — optimize things.