Me at 15: I'm never going to need Chebyshev distance in real life.

Also, while they simplified distance, they made finding you're in range of Fireball much, much more complicated. You can't just use the Pythagorean theorem to find out if the center of your square is in range. You have to use trig integrals to calculate how much of your square is inside the circle, and if it's more than half.