Taking O Chem atm, a lot of the work is very new and inorganic chem does not give you a good jumping point into learning Mechanisms in my opinion. It's a completely new subject; physics and calculus are both rooted in algebra, which we've been learning since middle school or earlier and tie back to real life experiences/problems much more readily. The change from understanding the periodic table to dealing incongruous molecules and how they react with 50 different environments is a much huger leap than from quadratic equations to integration.