I heard a good joke about this: when you're 20, you're obsessed with what others think about you. When you're 40, you don't give a damn what others think about you. When you're 60, you realize others were never thinking about you at all.
"Mr. Roark, we’re alone here. Why don’t you tell me what you think of me? In any words you wish. No one will hear us."
"But I don’t think of you."
-Ellsworth Toohey and Howard Roark, The Fountainhead, Ayn Rand
Don Draper: "I don't think about you at all."
(The irony of this line is that Draper, in fact, was obsessed with one-upping Ginsberg the whole episode.)