Does regret weigh you down?
Regret shouldn't to be looked upon as a negative emotion. To regret but still find the strength to move forward is a sign of maturity.

The answer I’ve heard many people give is: 'I have no regrets.’ I understand that people are implying that they’re happy with their present and they’ve let go off their past but I’m still a little confused by their response.
My response would be, “I do regret the mistakes I made, some of them very much so. I wish I had known better at the time I made them. However, I’m grateful for the lessons they taught me and for the opportunity to grow that life gave me.”
I wonder if people don’t regret the mistakes they made, did they ever learn from them?
Because to regret is not a bad thing at all. It is symbolic of the fact that you understand you went wrong, that you could've chosen a different path and that you’ve found an opportunity to grow.
Mistakes are integral to a path of growth and to grow, we have to be humble enough to accept and regret them. To be proud of one’s mistakes is not something I understand. To be proud of one’s growth that stemmed from those mistakes, that I understand.
Regret is painted in a bad light even though its purpose is to help us move forward. So take time out to ponder over your mistakes. It is a positive sign of you learning and growing into a wiser and better human being.
To not know what regret is an absolute loss. Like every other emotion it exists for a reason but it is up to us to recognise that. And when you’re done regretting, let the emotion pass. Don’t get attached to it because that is just as harmful. Attaching to any and every emotion is harmful because emotions are meant to be temporary, not permanent (not even joy).
Have you thought about what you most regret and did you learn from that mistake before you chose to move forward?