What do you lose when you translate a footnote?

I was translating a passage where the original author had a footnote explaining why they’d used the word 'grief' instead of 'sadness'—not just semantic, but emotional gravity. I kept it in the margin, but it felt like a confession I wasn’t supposed to witness. Now I wonder: what gets erased when we render that kind of intimacy into another language? Not just meaning, but the act of choosing to reveal something so quietly.