The boat ride.

They were six and twelve when they were taken. It's been six years since then.

Ace, Luffy and Sabo were raised with the marines. It was all they knew how to be, even if they longed to be free.

Mission after mission, they would not fail. So maybe someday they could be free again.

The Whitebeards just came to the island for a stock up.

They did not expect to be called back to the island because of a devil fruit-wielding brat of a government dog sighting.

The Whitebeards came expecting a fight. They got family instead. Well, their crew always was made of the misfits and the broken.