I hadn’t heard of Sam Harris but will keep my eye out for him. The concept of “no self” or “non self” is especially hard to grasp for Western thinkers (myself included). I think it’s poorly named. My fuzzy thought is not that the self doesn’t exist (of course it does - here I am!!) but that it’s not what you think it is, not something at the center of the stories we all weave/tell about ourselves. Recognizing that, a person may move towards a less self-centered world view.
I’m borrowing words from a Zen teacher/author here.
If you are interested in more on this concept, check out the late Derek Parfit. Here's a profile from 2011: https://www.newyorker.com/magazine/2011/09/05/how-to-be-good