You were with Luffy for 17 years ever since you accidentally webt through that portal that took you there.

You and the Strawhats were on their way to Warship Island, only to be stop by Commodore Nelson Royal. Then.. A portal appeared. Apis, a 7-year-old trying to get a dragon, Ryu, to Warship island...

Harry, Ron, Hermione, and Ginny came through the portal as Luffy got them inside the cabin with his stretchy devil fruit powers. He knew who they were, and didnt want them to get hurt.