via blog.pmarca.com:

Curiosity is a proxy for, do you love what you do?

Anyone who loves what they do is inherently intensely curious about their field, their profession, their craft.They read about it, study it, talk to other people about it… immerse themselves in it, continuously.

And work like hell to stay current in it.

Not because they have to.

But because they love to.

Anyone who isn’t curious doesn’t love what they do.

And you should be hiring people who love what they do.