Your Biggest Regret

You have heard that after you die, that you get to relive your entire life. Now that you're 95 years old and inside a nursing home. You think back and remember your biggest regret. And once you feel that your time has come, you pass away. Peacefully in your sleep. Just to open your eyes and... you're young again. Is this you just reliving your life? Or is this a second chance? Can you change the past?