No Self

It's often said that “there is no self” but it would be better stated as “your self is not what you think it is”. We tend to think of the self as a permanent thing that lives in our head and makes us who we are. No self says that's bunk, there's not a single thing in your head, there's a lot of processes happening in your head and your “self” is the current output of those processes. But as the processes are ongoing the you of now is not the you of yesterday or tomorrow.

In Buddhism, the term anattā or anatman is the doctrine of “non-self” – that no unchanging, permanent self or essence can be found in any phenomenon. While often interpreted as a doctrine denying the existence of a self, anatman is more accurately described as a strategy to attain non-attachment by recognizing everything as impermanent, while staying silent on the ultimate existence of an unchanging essence. – Wikipedia