Interesting question. When I think of no-regrets, I think of using my acknowledged mistakes of the past to propel me forward and grow. Regret is that feeling of being stuck on an issue that occurred and is over now but you never really learn or move on. In that sense, I live a life on no regrets because I use these opportunities to understand my mistakes, lack of actions, etc., in order to avoid them in the future.
People may have different definitions of what it means to regret.