To determine how to be most useful, consider the utility delta of your idea compared to the current state and how many people it will affect.

It's beneficial to create something that makes a significant difference for a small to moderate number of people, or something that makes a small difference but impacts a vast number of people.

When estimating the probability of success, focus on how useful your idea will be and the area under the curve it represents.

Starting a company can seem insane if the goal is to achieve the best risk-adjusted return, but that wasn't my objective when I founded SpaceX.