Meaning of becoming “entirely” forgetful of self

As to the fact that man must entirely forget himself, by this is meant that he should arise in the mystery of sacrifice and that is the disappearance of mortal sentiments and extinction of blamable morals which constitute the temporal gloom, and not that the physical health should be changed into weakness and debility. ('Abdu'l-Baha, Tablets of Abdu'l-Baha v2, p. 243)