There are better ways to exercise your brain that will be many more times better than Calculus. Maybe. And there are probably better ways to exercise your brai

There are better ways to exercise your brain that will be many more times better than Calculus. Maybe. And there are probably better ways to exercise your brain than memorizing cities, mountains, seas and rivers in countries you're never going to visit. But that doesn't make any of that useless. All that knowledge, calculus included, makes you know how the worls is structured, wether you're going to pull the levers yourself or not. You can't decide you're not interested in something if you have no idea how that something looks, even superficially.