Philosophy, surprisingly enough!
In high school, I had both the passion and the extreme hubris to think that I was prepared to write about philosophy. I created my own, not terribly well-considered world view that I labeled "Moderationalism," wrote a treatise on the subject, and flogged my ideas to any poor soul who had the back luck to cross my path.
I simply had no choice. I was determined to find the answers to life's questions before I had to leave for the "real world." Nothing could dissuade me.
As a freshman, I managed to convince my advisor to let me take David Lewis' upper level "Metaphysics of Time Travel" course. Despite my advisor's warnings and my total unpreparedness, I rationalized taking the course to myself with the recognition that the course was offered every other year, so I couldn't afford to wait. As the only freshman among junior and senior concentrators, I was, of course, thoroughly thrashed grade-wise, but loved every minute of it nonetheless.
I left for Japan in order to put to rest a logic puzzle that vexed me throughout my senior year: I had heard that in Japan, "Yes" doesn't necessarily mean "Yes" and more particularly that "No" doesn't mean "No." How, I wondered, could a language persist and a culture flourish without even such a basic grasp of logical primitives?
Determined to find the answer for myself, I left to teach English in the Japanese countryside and then to work at the feet of a Japanese politician (who was better able than most to twist the meanings of words.)
I'm a manager and angel investor in a range of Japanese Financial technology (Fintech) firms. I love the process of finding promising customer needs and marshaling the resources to bring them to reality. [This interview was conducted in 2016.]
Although after 20+ years in Japan, I've answered the question of the meanings of "Yes" and "No" to my own satisfaction, I've utterly failed at my primary goal for my philosophy training. I'm embarrassed to admit that I haven't discovered the secrets to life's questions.
Just the same, I think my professors in the Philosophy department actually provided me with something vastly more valuable - tools to see through to underlying causes and understand the world deeply. I have no end of gratitude for their patience with an arrogant kid and no end of awe for their ability to expose me to the richness of the world of ideas.