For most of the early hires you make in a startup, experience doesn't matter very much, and you should go for aptitude.
No matter what you choose, build stuff and be around smart people.
Startups are very hard no matter what you do; you may as well go after a big opportunity.
There's no way I know, to get through the pain of a startup without belief that the mission really matters.
Before product/market fit, your only job that matters is to build a great product.
The single word that matters most I think to keep the company productive as it grows is alignment.
Experience matters for some roles and not others.
It's become popular in recent years to say that the idea doesn't matter.
I myself used to believe ideas didn't matter that much, but I'm very sure that's wrong now.