I didn't start college with the idea of being an applied mathematician/computer scientist/computational scientist/whatever the heck I am. I had really enjoyed chemistry in high school, and I was interested in superconductivity and materials science, so I decided to major in chemical engineering.
Then, I took my first chemical engineering course, "Process Principles," and I hated it! It wasn't that it was hard; I think I got an A in the course, but I just didn't like it. What I disliked was all this tedious arithmetic that was used to compute chemical concentrations of huge vats of chemicals and the like. By that point I was in the first semester of my sophomore year. I was taking Organic Chemistry, Computer Science for Engineers, and Physics for Engineers (second semester, Electricity and Magnetism), along with some other courses satisfying my humanities and social science requirements. I decided that I needed to change majors, so I looked through the catalog and tried to figure out what I could change to that I wouldn't be too far behind to graduate on time.
I saw that I could major in Physics without being behind. And I could still pursue my interests in materials science with a Physics major. So I switched to Physics at the next opportunity. My Physics professor was pleased, as was the professor I'd had the previous semester.
Physics was a fairly small undergraduate major, and there was one other woman in my year. We were lab partners a lot, I remember. She's now a first-year professor of astronomy in a neighboring state. I spent the summer after my sophomore year at a summer internship, simulating Physics (photonics, actually) on a computer, and quite honestly I had the time of my life. When I got back to school and started taking harder classes, I started to become uninterested by my coursework. By my senior year, I had reached a crisis point, and I didn't know what to do. I didn't want to continue on in Physics, but I didn't know what else to do. I remember talking to one of my professors in his office and crying because I was confused. But I talked to a few computer scientists and decided to maybe try to get into graduate school in computer science.
One big influence was my numerical analysis professor. My B.S. in Physics had a concentration in Computational Physics, meaning that I took something like three computer science courses. One of them was a numerical analysis course, taught by a professor who came recommended by one of my friends. I don't remember much about that course, except that "subtraction is bad" (it can lead to catastrophic cancellation), and the fact that on one of my homework papers, the professor wrote, "Have you considered graduate school in computer science? I would love to have a student like you!"
I took him up on that sentiment and applied to graduate school in computer science, both there and at a couple of other schools. I got into two places, Kentucky (winning a fellowship), and the University of Illinois, and I chose the better school (Illinois). I think he was very disappointed when I went elsewhere, but actually, it's interesting, my dad recently saw that professor. They were both serving on a committee for the university, and although he didn't immediately recognize my name when Dad told him that I might have taken a course from him, he later figured out who I was and was thrilled to know what I was up to.
Once I was in graduate school, I knew what I wanted to do, or so I thought. I knew I wanted to simulate science on a computer, but I was kind of scared of computers. Coming from my background, I was pretty good with computers, but compared to all the people with computer science degrees, I was pretty ignorant. I was overwhelmed by all the acronyms and terminology, and I thought I would never be able to learn all that stuff.
And my courses were very challenging, too. Here I was, learning all this stuff for the first time, while competing against people who had much better computer science backgrounds. I got through my core courses with 2 A's, an A-, and a B (only slightly better than the minimum requirement of 3 A-'s and a B-). Those first two years were very stressful, and I was afraid I wasn't going to make it.
It took a while, but I've learned a lot of computer science. I'd say I can hold my own in the field. Compared to many of my classmates and colleagues, I really know a lot about computing, and parallel computing in particular. But it didn't come easily at first. It took a lot of coaxing by my advisor before I would even take the risk of admitting that I needed help.
I have to say, I really love the work that I do. I think that I inadvertently found a field that I really fit into. When I was graduating from high school, I don't think I would have thought of doing what I do, in part because I hadn't really heard of it, but also because I wanted to be an experimentalist of some sort.
I'm not really sure what the point of this post is, except to just describe the convoluted path I took to the career I have now. I'm really glad that I found this field!