When a precocious yet nonconformist teenager asks why they need to learn calculus, what should you say?

You know they will never use it in adulthood, outside of certain career choices.

You could say, “It’ll help you get into college,” but then they’re left wondering why college cares if you know calculus. And once they’re in college, maybe you could say, “To get a good job,” but why would a potential hirer care how you did in multivariate calculus if your job doesn’t require any knowledge of calculus?

...But I recently realized there is a very good reason to take Calculus. It’s to prove you can do hard things.

The ability to do hard things is perhaps the most useful ability you can foster in yourself or your children. And proof that you are someone who can do them is one of the most useful assets you can have on your life resume.