Then who? If you end up referring to yourself in the third person, that's a bit odd; having a conversation with yourself in the second is probably not a good sign! Your "character" has no mind, no personality, no real existence at all. It is no more than a persona, like the masks that actors wore in the ancient Greek theater.Ahh but that is not me now is it?
But D&D is not really theater, or puppetry, or a novel. It's not just a war-game, either -- certainly not in the sense of an algorithmic model that chugs away on automation and spits out a report!
If one's only purpose is to "put on a show" that has no real effect on the game, then how really is it a game? If there is simultaneously something separate that is a game, then how is that different from performing one's "Hoppy the Hobbit" routine while playing Canasta or Command and Colors?
Integration is key. D&D brought forward a game form in which playing a role was how one played the game!
Again, it's fine and dandy if you happen to like "acting the part" to an appropriate degree. Of course, Hoppy the Hobbit is not exactly the same as you! But don't put down the guy who imagines "himself, as he likes to think he might be" in Hoppy's place. There in fact is nobody else to motivate that imaginary frame, to see through those eyes and feel the chills that might be but dungeon drafts or ... something ominous. There is no other will to make Hoppy's choices, no other heart to feel his feelings.
Hoppy the Hobbit cannot play a game. A mere collection of numbers cannot be challenged. That takes a real person.