Don't remember who said it but it was from some celebrity or something who got divorced at the time. When asked about if he/she regretted it, they said something along the lines of "If it was everything you wanted at the time, then there is nothing to regret."
9/10 times people make the best decision in any given situation with the information they have, and their ability to evaluate the decision. As time goes on, we naturally gain more of both. That being said, never regret making a choice because of what you know now. It is impossible to have known, and thus gave you the experience that helps you move forwards, presently.
Definitely stuck with me all this time.