When I went off to college, I was undecided as to whether I would major in chemistry or physics. Both subjects fascinated me, and on top of that, science was the subject to be taking. To date myself, that was just a few years after Sputnik, and the United States was in a science frenzy and locked in the space race against the Russians. Today we are talking STEM (science, technology, engineering and mathematics), essentially the same thing.
I soon decided that chemistry was my preference, since physics had so much advanced math that I wasnt interested in doing. After my first two years of basic chemistry, I started getting into upper class subjects, including physical chemistry, affectionately known as PChem. Id been warned by others that PChem was a real shock to the system, and they were right.