"Don't surround yourself with yourself" - Yes; I've Seen All Good People (The Yes Album); 1971
Andrew Farmer and Cole Houston are back to face off on a weighty issue that confronts many a comic book hero. This would be, of course losing oneself in one's alter-ego.
When someone loses themselves wholeheartedly in their secret identity their "other self" can exert control to the point that they are lost within that self.
Batman tends to spring to mind first, but there are many other examples sited. Beyond a hero becoming too much the mantle thereof, your hosts also explore examples of alter-egos taking on alter-egos of their own!