What was the biggest mistake you've done, and how did you made it right?

Ruining things with my first love deliberately through reasons and won't go in to. With maturity I realised how wrong and naive I was so after a lot of searching to find him, I finally contacted him and apologised. To which hr appreciated and accepted.

Worst mistake in my life, I got too much in love with a lady on EP and she left me. Don't think I can repair it. Would do anything she asked but she's gone

Only not keeping people out of my life sooner, but I did it and I'm better for it :)

All I can say is 90% of mistakes are unrightable.