I have 2 criteria for picking an idea I actually want to work on: - One is how many days consecutively am I still thinking about the idea without forcing myself

I have 2 criteria for picking an idea I actually want to work on: - One is how many days consecutively am I still thinking about the idea without forcing myself - Second is even if no one uses it and everything about it's progress is shitty, will I still want to keep working on it?