You can sometimes learn as much from things done badly as things done well. Sometimes it only becomes clear what's needed when it's missing. - Paul Graham

You don't need to know more than the most obvious things about business to start a startup, but you need to be at least decent at building things, in order to build sufficiently good initial versions.

In many domains it's an advantage to have a culture of doing things fast and cheaply. But organizations never shift toward this as they age; if they shift, it's always in the other direction. So the only way to have this culture is to start with it and not lose it.

The stated purpose of schools is to educate the kids. But there is no external pressure to do this well.