How to handle a "nagger-spouse"?

My ex-husband was such a nagger. He would nag about the same thing repeatedly over and over and over again, sometimes 2-3 times in a row but phased differently. After a while, I mastered the art of filtering and zenning out each time he nags. It works, he thinks I'm listening and we move on. It's horrible yes, but it beats flaring up and getting into minor fights all the time.