I'd add to that and say Vivi didn't just teach him to "bow", more specifically she taught him that you can't solve every problem with fists. You can't punch your way out of everything, and even if *_you_* can, as a leader, you have to consider thoes with you
I really don't know why but Momo's and Oden's moments don't make me emotional. What brought me to tears here is Luffy's point of view and how he even stopped him from bowing his head, so warm and admirable 🤧❤️