I did not go on in Classics, however, my studies served me well in the study of law. Understanding even the most obscure legal theories pales in comparison to figuring out the proper use of the middle voice in Greek. Being able to parse Latin phrases was also useful, even if only to show off at cocktail parties. As my career has progressed, my Latin and Greek abilities have atrophied. However, the discipline I gained from my daily struggles with Ovid and Plato (among others) remains.
Open Source Licensing Counsel
Intellectual Property and Licensing Division, Microsoft Corporation