You can never regret anything you do in life. You kind of have to learn the lesson from whatever the experience is and take it with you on your journey forward.
Never regret anything because at one time it was what you wanted.
At the end of your life, you will never regret not having passed one more test, not winning one more verdict or not closing one more deal. You will regret time not spent with a husband, a friend, a child, or a parent.