What motivated you to world build?

As someone who struggles with low motivation and wants to try world building, I'm curious. What motivated you to build your world? How long have you been building it, and how do you stay motivated enough to keep writing it? I've known people who have worked on their world for many years, and it really impresses and inspires me to world build as well. I haven't really done creative writing since high school, and would love to get back into it.

I hope this has enough context, I'm new to this sub and didn't really understand the rule all that well.