There’s a good idea inside you, you just don’t know if it’s the 1st idea or the 100th idea.
You need to make 100 ideas in order to find out.
You may be able to narrow it down to 10, and then struggle from there.
You may need to ask people to help you pick which one is the best one. Or for them to talk you out of the one you picked.
It may take you years to do it; just to get to the starting line, to find one good idea. Then you need to execute.
In this sense, while ideas are cheap, a good idea is expensive; it can take a long time to develop.