Related, my favorite paper title of all time, "Robust Soldier Crab Ball Gate" [1], demonstrating how soldier crabs can perform functionally complete reversible computations.
Another way to put it: each step in a reversible process must be a bijection, or "information-preserving". The naive way to do that is to return the entire input as part of the result, but that's missing the point.
2. If you take a step back and look at the things you argue with your significant other about (or anyone else close to you), it's humbling to see how silly it often is.
3. Love doesn't always agree; if you actually hated the person, why would you stick with them through the annoyances and arguments instead of leaving?
Sure, the whole thing seems unhealthy and petty, but I think that he would have stopped writing a lot sooner if he didn't truly love her. I also think the slightly-hidden image at the very bottom left of the page says a lot more than any of his words do.
[1] https://arxiv.org/abs/1204.1749