live (something) over again

1. To remember very vividly a particular episode of or sequence of events in one's life. I really regret the way things ended between us, and I've been living the argument over and over again in my head. I keep living that moment over again trying to figure out what I did wrong.

2. To (hypothetically) relive a specific portion or period of one's life, typically in order to do something differently. If I could live high school over again, I definitely would have hung out with a group of friends that might have been a better influence on me. I would definitely move to Japan to teach English for a couple years if I could live my twenties over again.