When you were young, you wished that you could grow up fast to be able to drive yourself, to do what you want to. When you were at school, you wished time could fly so you can be a adult person, and be able to decide your own life.
But do you know that all adults want to turn back the time when they were still young and went to school everyday? Not because they regret something in the past, but they have realized that time goes by too fast and their life is too short.
They want to take back the time and hold back the beautiful moments as well as lessons in their life. But it will never come true.
Time will never come back. What was done will be undone. You can only live in the present, and hope for the future. The past is the past.
So, instead of regreting the past, you just need to enjoy every moment of live. Live a unregretful life!