I have to ask....are you in his league? I know your education doesn't match, but what about ages/sophistication/social circle? Some may call me a snob, but most people do tend to date others who are from a similar background.
You don't say much about yourself, so it's very hard to gauge what your chances are. What qualities do you have which would attract a man of this calibre?
Does he have a girlfriend or wife? Don't judge by the presence of a ring - not all guys wear them.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.