About how long do you need to immerse yourself in a project before you can confidently say you have finished worldbuilding it?

I’ve been pondering this question for a while, and I thought that this sub would be the perfect place to ask it. <br>I’ve been working on a project for the last few years, and I’ve created a lot of lore for it already. But for whatever reason, it still doesn’t feel finished. I’m wondering when does everybody know when they’ve finished building their world? Has anybody been there?<br><br>TLDR: When do you know you’ve finished worldbuilding something?