Obligatory http://xkcd.com/435/
In retrospect, I should have been a coder. Although all my coding adventures post high-school have basically been autodidactic, I jumped in the deep end and took a high-level undergrad/grad CS class and coded my own web server... I was the only person whose server didn't allow the user to drill through the directory structure and hack the server because at the time I didn't know the posix file functions and actually wrote my own string parser/handler.