Words—and syllables or semes—accrue a sense of meaning through a history of associations, so that outside of a particular context these verbal units seem to possess meaning in themselves. If I say “dog” the almost universal reaction will be that I am referring to a particular species of animal. This meaningfulness of words in themselves has been thoroughly demonstrated to be an illusion. Words don’t “have” meanings. Words create, conjure, or negotiate meaning through actual use. Only in actual contexts, which include but are not limited to strictly verbal contexts, do words effect meanings. And any word is capable in a given context of stripping all or nearly all of its historically associated meaning. The bond of the meaning to the word is in fact so weak it can be stripped away by the merest suggestion: “From now on every time I say ‘dog’ I mean ‘house.’” What may begin as a comic substitution with short use will simply become a new meaning for the word.
Egos work in the same way. We develop through experience, each of us, what we call a personality--our "identity." But this personality, these traits by which we define ourselves and by which others define us too, can be stripped away with alarming quickness when we are put into contexts in which they are inappropriate. People’s characters are overwhelmingly situational.
Keep that in mind.