Carrying regret is a burden that never improves the present ( where we should strive to be). Here’s s buddist story that I use to remind me of that:

The tale of two monks and a woman is a well-known Buddhist parable. The story goes that two monks were traveling together, a senior and a junior. They came to a river with a strong current where a young woman was waiting, unable to cross alone. She asks the monks if they would help her across the river. Without a word and in spite of the sacred vow he’d taken not to touch women, the older monk picks her up, crosses, and sets her down on the other side. The younger monk joins them across the river and is aghast that the older monk has broken his vow but doesn’t say anything. An hour passes as they travel on. Then two hours. Then three. Finally, the now quite agitated younger monk can stand it no longer: “Why did you carry that woman when we took a vow as monks not to touch women?” The older monk replies, “I set her down hours ago by the side of the river. Why are you still carrying her?”