Luffy remembered the long first time he met Robin.

It started with puzzlement. Good guy? Bad guy? What? What?

Confusing. Very confusing.

But he decided to be patient and wait the confusion out.

Normally he's never patient for anything.

But Robin was Robin.

Was she good? Was she bad? Blegh. Too confusing to figure out, and it didn't matter after a while anyway. It was Robin, and that's all he needed and wanted to know.

Robin had a devil's fruit that let her grow different parts of her body.

Luffy always knew which hands, arms, limbs, eyes, faces, were fake. It was easy.

And Robin was nakama.

So he waited patiently for when he could see her real face.

It would take a while. She had many different faces.

But they were nakama. What else would he do but be patient for her?

So he'd waited.

Alabasta.

Skypeia.

And then, of course, Water 7.

And now she was just being stupid, saying she wanted to die.

Like he was going to let that happen.

She didn't seem to get that. And Robin was smart, so he didn't get why she didn't get it.

So, after a long while of waiting for Robin to finally get it, he'd gotten impatient. He wasn't a patient man to begin with, and besides, it wasn't fair of her to say that when they wanted to protect her. And then, she went off to save them by herself. Save them by dying, no less. Nope. Robin wasn't playing fair at all.

So he declared war on the world. So what? Since Robin wasn't being fair to them, they wouldn't be fair to her. If she wanted to die for them, then they would die for her. Hmph.

And then, she said she wanted to live.

She wanted to live.

It was the first time he'd heard that since they sort of met in Alabasta.

Ah.

Robin's true face at last.

A long, oh so long, turtle slow impression.

And that's the long version of how Luffy met Robin.

The short version, of course, is that he saved her. The first impression was confusing, saying dangerous, a lone wolf, but the second one said she wanted, and needed, friends, a family. Why else would she go with them?

But that's how the long story goes too.