It is the suggestion that what you have experienced as a separate ‘me’ is and always has been only an appearance.
What is being suggested here is that there is in actuality no such thing as a separate individual, or anything at all that exists in and of itself.
It is the really felt contracted sense of being separate to the world that gives rise to a yearning for wholeness.
In other words, what we are all searching for, in myriad different ways, is to not be a separate ‘me’ and be complete and whole. So whether I am trying to make a million euros or searching for spiritual enlightenment through becoming increasingly meditative and mindfully aware, what I am actually looking for is to not be a separate person, to be whole and complete.
Another way of saying this is that I am in fact searching for my own absence (not my expression, not sure of the exact source to reference it).