Why does Buddhism say "man has no self"?

What Buddhists call "man without me" is to get rid of people's general attachment to "physical self" (ignoring spiritual existence)! Most people regard their bodies as the real "me". They are busy all their lives and work around this body. Buddhism believes that this physical "I" is a temporary illusion formed by the "four false combinations" of earth, water, fire and wind; Once the "four points" occur, people's consciousness will re-enter the "six divisions in the wheel of karma" with the karma of good and evil, or rise to the "four saints" status of arhat, Buddha, bodhisattva and Buddha due to practice. For anyone else, the same reason! In other words, you can't be obsessed with "me" or "people"! So it's called "a man without me"! In fact, this involves breaking the two obsessions of "self-attachment" and "human attachment" (and the latter can include the former). If we reach a higher level and understand the cosmic reality of "one true Dharma realm, all things are vacuum and all things are integrated", we need to let go of this spiritual "I", which is the so-called "learning from Buddhism and returning to nature"!