Anything about love or romance. But Luffy remembers those stories that Robin reads to him, sometimes with a Prince and princessโand they live happily ever after, in marriage. Luffy also knows that Boa Hancock plead with him to marry her because she loved him, which he declined, so, he remembers that, too.
If you marry someone, you like them a lot, right?
Luffy likes you. He wants to hold you, and listen to your heartbeat. He wants to hold hands and skip down paths on new islands. He wants to kiss you, even if he doesnโt know what that means โ heโs only heard the word from Sanji. When heโs Pirate King, he wants you to be right there with him.
When heโs having a banquet with all his friends, he wants to sit next to you. You make his heart feel nice, you make him smile! Hell, heโd share his food with you if thatโs what it would take!! Though, heโd probably try something else before doing thatโฆ