How would you interpret the fourth sentence?
How would you interpret the fourth sentence “That’s a new one on me”?
Thank you.
PS: the excerpt is taken from “Missing Kissinger” written by an Israeli author, Etgar Keret. And I’m reading an English translation.

the context:
She says I don’t really love her. I say I do, I think I do, but I don’t. I’ve heard of people who say they don’t love somebody—but to decide for somebody else if they love them? That’s a new one on me. True, I had it coming. If you go to bed with a skunk you shouldn’t cry when your kids stink.

Question

How would you interpret the fourth sentence?
How would you interpret the fourth sentence “That’s a new one on me”?
Thank you.
PS: the excerpt is taken from “Missing Kissinger” written by an Israeli author, Etgar Keret. And I’m reading an English translation.

the context:
She says I don’t really love her. I say I do, I think I do, but I don’t. I’ve heard of people who say they don’t love somebody—but to decide for somebody else if they love them? That’s a new one on me. True, I had it coming. If you go to bed with a skunk you shouldn’t cry when your kids stink.

Answer

"That's a new one" or "That's a new one on me".... these are expressions you say when you hear something a little bit surprising or unexpected. But this phrase also adds a little bit of disbelief. People often say it when they are being mildly sarcastic. If you use this expression you are saying something like this..."I've never heard anyone say that before, and there is a good reason for that, because what you just said was a little bit silly".

Example...
"what is your favourite thing to drink?"
"I love goat urine, it's so healthy!"
"that's a new one one me."

Answer

According to what I have found by searching, that means "I'm surprised".

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