The problem isn’t so much whether regret is an unproductive emotion. It’s that regret occurs after the fact, instead of before. As Nietzsche points out, regret can do nothing to change what has already happened. We just wallow in remorse about something over which we no longer have any control. But if regret occurred before a decision instead of after, the experience of regret might get us to change a choice likely to result in a bad outcome.
