In general don't start a startup you're not willing to work on for ten years.
... but the pendulum has swung way out of whack here. A bad idea is still bad, and the pivot happy world we're in today feels suboptimal.
You want an idea that turns into a monopoly. But you can't get a monopoly, in a big market right away; too much competition for that.
At YC we have this public phrase, and it's relentlessly resourceful.
Cofounder relationships are among the most important in the entire company.
As you grow, the productivity I think, goes down with the square of the number of employees if you don't make an effort.