Okay kiddo, so Jon Kabat-Zinn is a man who is really good at helping people understand how to calm down and be happy.
He teaches people how to do something called mindfulness, which is a fancy word for paying attention to what's happening right now. This can help people feel less stressed and more peaceful.
He has made books and videos that explain how to be mindful, and he even teaches classes where people can practice together.
Lots of people really like Jon Kabat-Zinn because he helps them feel better, and that's a good thing!