Brook was half-heartedly playing his violin on the deck of the Sunny, random melodies chained together with the occasional snippet from Binks' Sake, when he felt something touch his hair. Sooner than his brains caught up (though he didn't really have brains!), his hand shot up to protect his precious afro, and he felt the bow in it hit something soft. Turning around, he saw no one, but from the upper deck he heard a soft "Ah!" that gave away their archeologist's hiding place.
Understanding she had been spotted, Robin stood up and smiled at the skeleton in her mysterious way. "I'm sorry to have bothered you", she said, undisturbed by the fact that her weird actions had come to light. "Your hair's so weird I wanted to know how it feels."
"Ah, that's fine", Brook said, smiling at her, though of course he couldn't smile, being a skeleton. "My hair's my pride! It's very nice to hear it's been on your mind. Yohoho!"
"That's good", she said, coming down the stairs onto the grass-covered deck. "Can I ruffle your hair some more, mr. skeleton?"
"Go ahead", he said, laughing again. Robin used her devil's fruit power and made arms bloom on his shoulders. The skeleton's laugh faded to a nostalgic smile when he remembered how his previous captain had used to pull on his hair in the most random situations. And one time when he had fallen in the sea, Laboon had pulled him ashore by his afro, resulting in him being stranded on a deserted island while the young whale fetched his crewmates who hadn't yet noticed he was missing, and catching a cold.
When she'd had her fun, Robin removed her extra pair of arms from the musician's shoulders and leaned back against the ship's wooden wall. After a while she noticed how still the skeleton was standing, lost in thought. She was just wondering whether to ask what was on his mind when their captain's hands came flying from the other side of the ship and grabbed the mast. After them bounced Luffy himself with a piece of meat in his pocket and his cheeks stuffed with more food. He crashed straight into Brook who came out of his daze a moment too late.
"Luffy!" he cried. "What are you doing? My heart almost stopped!" and after a short pause, he laughed. "I don't have one though! Yohohoho!"
"Nihihihihi!" Luffy joined in. He loved Brook's jokes, though the skeleton himself mostly made them out of habit rather than because he found them very funny. The little captain jumped off Brook and swallowed the food he had stored in his cheeks. The skeleton got up too and noticed his skull had opened and the shell inside had rolled away. Before he had time to get worried, Robin handed it to him with the help of a few extra hands.
When the musician was putting it back inside his head, Robin made up her mind and asked: "Are you alright, Brook? You seemed a little lost in thought just now."
"Eh? Is Brook feeling down?" their captain asked, mouth full of meat.
"Ah, no, I'm fine", the musician answered, a little flustered. "I just remembered some good memories. It seems I have developed a habit of getting lost in thought. Yohoho!" and he proceeded to pick up his violin, which had fallen to the ground when Luffy had made him fall. It was luckily intact, though a little off-key. He started tuning it, but was disturbed again by the captain hanging from his afro.
"Can I be in your hair when you play?" Luffy asked. "Let's have a singing party tonight!"
And they did, of course, because their captain wanted to, and they had plenty of food at the moment (though Sanji kicked Luffy for having stolen a rather big amount of it again). Luffy asked for Binks' Sake to be played four or five times, Brook wasn't quite sure due to his lack of memories from late night caused by some excellent beer.
Thinking about it, Brook realized he hadn't been remembering the old times nearly as much as before after becoming one of the Straw Hats. - Of course; he had new things to think of now, new adventures to face everyday. "I hope you don't mind, Yorki", he mumbled to the pre-sunrise darkness in the cabin. And he knew what his old captain would've said so well he could almost hear it:
"Hahaha! Are you getting emotional as you grow old, Brook?