I knewww itttt!!!!

he couldn’t have written a letter cuz he would have forgot to

This. I genuinely don’t understand why he didn’t use the time before the surgery to write down all of the important things in his life and have that there when he woke up from surgery. I get that the uncertainty kept him from telling her, but I would think he’d still take something with him to remember her by, like a photo or anything.

Maybe he thought he didn't have any chance to live.

I guess, but he had to have at least a modicum of hope to even go through with the surgery at all. Also, I’m a little surprised he had no photo of her, nothing of her at all, even to just hang onto until he died because it’s clear that he loved her very deeply.