I am not entirely certain, but I think a great part of it might have to do with what I associated “science” and “engineering” with when I was a kid. Even when I was little the idea of scientists in white coats was a bit weird. I had seen them made fun of in cartoons enough to appreciate a caricature. My grandfather worked in a hospital lab and for me such lab coats were for doctors.  I never could put my finger on it until recently but as I have went back through the franchises I enjoyed as a kid, I finally realized who I wanted to be: