Quote 1
"I shouldn't know you again if we did meet," Humpty Dumpty replied in a discontented tone, giving her one of his fingers to shake: "you're so exactly like other people."
"The face is what one goes by, generally," Alice remarked in a thoughtful tone.
"That's just what I complain of," said Humpty Dumpty. "Your face is the same as everybody has – the two eyes, so – " (marking their places in the air with his thumb) "nose in the middle, mouth under. It's always the same. Now if you had the two eyes on the same side of the nose, for instance – or the mouth at the top – that would be some help." (Looking-Glass 6.111-113)
To us as readers, Alice seems individual, but to Humpty Dumpy she's "exactly like other people." Our uniqueness depends on how detailed our definitions of identity are. Alice may have two eyes on top, a nose in the middle, and a mouth underneath, but surely the specific color of her eyes or shape of her nostrils is distinctive.
Quote 2
"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean – neither more nor less."
"The question is," said Alice, "whether you can make words mean so many different things."
"The question is," said Humpty Dumpty, "which is to be master – that's all." (Looking-Glass 6.63-65)
Humpty Dumpy believes that he can exercise total control over language. Unfortunately, as Alice realizes, if he makes words mean anything he wants, then nobody can understand him. People have to agree on shared definitions and meanings for communication to be possible.
Quote 3
"I meant by 'impenetrability' that we've had enough of that subject, and it would be just as well if you'd mention what you mean to do next, as I suppose you don't mean to stop here all the rest of your life."
"That's a great deal to make one word mean," Alice said in a thoughtful tone.
"When I make a word do a lot of work like that," said Humpty Dumpty, "I always pay it extra." (Looking-Glass 6.68-70)
Humpty Dumpty's arbitrary redefinition of a word means that he has to explain himself anyway – making the word totally irrelevant to the conversation.