Another problem is, if you are out of university or high school without much experience in really any field, what exactly are you going to build, you have no real specializations and are a blank state, so you can work with what you do know a little about... music? recipes, travel? existing consumer web apps that are easy to code (and then coding it and realizing marketing is the real challenge for them).
Wondering what Paul G. thinks of this.
It should be noted that the world will never know how many tried and failed to do what Stripe succeeded in.