I really hate the imperial system for cooking and wood working because it involves many unnecessary fractions, which necessitates finding common denominators in order for my brain to understand any comparisons. I always use centimeters or millimeters if it's up to me.
In cooking, I have no concept of milliliters, and I'm usually following recipes anyway. But the measurements are annoying and require arithmetic: 3 teaspoons to a tablespoon, 16 tablespoons to a cup, and 16 cups to a gallon.
If I have to use any real math in real life, I am screwed.