“I'm ridiculous to feel ridiculous when I'm not.
You must
be laughing at me
for feeling you are laughing at me
if you are not laughing at me.”

Also sometimes attributed to Kurt Cobain
Variant: You laugh at me because I'm different, I laugh at you because you're all the same.

I
Variant translation: I am a ridiculous man. They call me a madman now. That would be a distinct rise in my social position were it not that they still regard me as being as ridiculous as ever. But that does not make me angry any more. They are all dear to me now even while they laugh at me — yes, even then they are for some reason particularly dear to me. I shouldn't have minded laughing with them — not at myself, of course, but because I love them — had I not felt so sad as I looked at them. I feel sad because they do not know the truth, whereas I know it. Oh, how hard it is to be the only man to know the truth! But they won't understand that. No, they will not understand.
As translated by David Magarshack
The Dream of a Ridiculous Man (1877)
Context: I am a ridiculous person. Now they call me a madman. That would be a promotion if it were not that I remain as ridiculous in their eyes as before. But now I do not resent it, they are all dear to me now, even when they laugh at me — and, indeed, it is just then that they are particularly dear to me. I could join in their laughter — not exactly at myself, but through affection for them, if I did not feel so sad as I look at them. Sad because they do not know the truth and I do know it. Oh, how hard it is to be the only one who knows the truth! But they won't understand that. No, they won't understand it.

Source: Drenai series, Legend, Pt 1: Against the Horde, Ch. 9

From the song "Rubber Ring"
From songs

Tigerbeat interview (2006)

pg. 220
Pretty Mess book (2018)

Source: Pride and Prejudice

I was touched by the tenderness of his tone, and asked why.
“Because I know!”
Professor Van Helsing to Dr. John Seward, in Dr. Seward's Diary entry for 22 September
Dracula (1897)