Would You Rather; Bad Dreams
4yo: Mom, would you rather eat ice cream or eat POOP?
Mom: ?!
4yo: Ha ha ha!
ChatGPT has no sense of humor.

I think the baby had his first bad dream. Somehow, the cry was noticeably different than the usual dirty diaper or I'm hungry cry. In either of those cases, the problem can be fixed; the crying immediately subsides. In the bad dream situation, he had to be calmed down, with considerable effort. Maybe it was a dream about his visual cortex fighting off intruders. Or maybe he was dreaming about how his all-milk, no-exercise diet might lead to having three chins instead of his current double chin.