Usopp growing up, finding out what friends are, and being happy.
Laughter is always jovial and open, eagerly available. He's happy. Maybe not so much since the townsfolk have a mean streak to his mischievous one. Adults, bah! All they want is... what he also wants, he realizes. What a find!
And friends too, right? Then it happens one day. Dreams do come true! (He is imagining all of this.) He creates beautiful and everything nakama. He can't wait to plan and make adventures with them! All these years of imagining and storytelling and ooh! Waiting with his heart pounding-all just practice for something amazing, spectacular, and utterly /unbelievable/. Something great, his child-heart and -lungs comprehend. He can feel it in the marrow of his bones and the loops and corners of his head.
Something's waiting for him beyond the fear and the laughter; it's sitting out there, and he's going to get it.
He feels like flying, only pirates--what an astounding mouth-sensation-noise-thought the word makes!--can't! But it's even better, what pirates can do. (He feels like telling a story.) Like a mashed crusader, he'll enter the scene heroically, and bam! Swoop! He's fighting and working, and he's going to love it.
He wonders if they'll let him wear a cape and a mask. But of course they will; they're /nakama/, don't you see?
Then it happens, and it is like nothing he has ever dreamt. The shock of their prospering forms strikes him out of the proper way to hold the slingshot which he's had for /years/, so it's a huge deal, what are you saying!
It's sweaty in his hands, or perhaps his hands are sweaty wrapped around it tightly in admiration. The smooth handle and efficient structure is enough to make him yearn for skill and technique.
They're so different and he wonders if they're not going to like him, if he's not going to fit in, if, if...
He doesn't have any real friends yet, which he doesn't know, but only acquaintances; he doesn't know about /living/, adventure and the like so far. It's only inventing a past, building character now. The journey is one he is not aware of yet.
He is in pain and doubtful and trying his best, those eyes squinting at the target, hands releasing the shot no matter how fruitless it seems--this is all he has and he intends to keep and cultivate it--and running, running, yelling, and laughing through it all. Fast and important are the subjects he's learning, darting about them. He's becoming.
He has one horrible moment: their backs seem so terribly large compared to him. Luffy turns around, bounces back, and laughs at his own elasticity. It passes.
Then they finish it through confusion and all sorts of ugly things. He has friends, he thinks. He knows when they prepare to leave, and he's the one who has to say goodbye, not his follower--friends or his helper--friends. What surprises him, exceeds expectations, is that the Going Merry crew all say goodbye.
Searching for adventure, he's on his way, that is, if it doesn't find him first. He snaps his overalls (the suspenders) and puffs up his chest proudly.
First things first: they won't let him wear a cape. It's impractical, everyone besides Luffy says. (Luffy asked if they would be able to eat it if they got hungry.) He doesn't mind because it's blue out there, and much more majestic than things like worry and anger. In the wide blue, people are heroes but money isn't courage, and it's fine. He loves the sea.
One thing's still the same: there is an atmosphere here, about listening and feeling and hitting and success, something for him, which he's going to get, laughing at the starboard side and surrounded by people he loves, simply because he is here.