One of the consequences of the 5P-model for startup evaluation (Product + Problem + Profit + People = Potential) is that finding the right people is much more important than finding the right idea. So important, in fact, that you might as well begin with finding the right people before you even know what to build!
Why? Because of the 4 Ps that make up the potential (Product, Problem, Profit and People), the people P is the hardest to change once you get going.
You can (and should) iterate and improve your product.
You can (and should) validate and test your problem.
You can (and should) experiment with different business (profit) models.
But once you start, you can’t change the people.
Of course you can always fire co-founders but it is a painful and expensive process, much more so than pivoting on your problem definition.
So, instead of waiting for the right idea, go look for someone that complements you and is equally passionate about building something.
Then find out what to build.
(Discuss on Hacker News.)