‘Wu wo’ (无我) means ‘non-self’ (Anatta), which means that as there is no enduring (unchanging) entity in our body and mind (which are nothing other than the five aggregates of form, feeling, perception, volition and consciousness – each in constant change), there is no substantial (fixed) physical or mental thing within us that can be called ‘self’. That which we refer to ‘self’ usually carries the idea of something within us being unchanging and thus substantial.
There is on the other hand, something enduring, our Buddha-nature – the potential to become Buddhas. As this is not physical or mental, it endures. When we realise Buddhahood, this state of ultimate enlightenment endures too.