Alright so I've been sitting on this one for a while...
You know how we all kind of interpret Luffy as a bit of a dork or rather simple minded? What if he's actually just extremely smart?
For example, he always knows exactly what to say or do in any situation. He is for sure 'people smart' because he knows exactly what people need to hear from him. I will fight you on this.
Or how he's still alive. Tbh he should be dead by now but he always scrapes by with Devil's Luck. The most impossible coincidences happen with Luffy, and what if they weren't coincidences at all but noticed/planned by Luffy?
I'm not saying he's pretending to be his carefree and happy self, but I'm saying the way he sees the world is very clear and he has an amazing understanding of how the world and people work.
I know this theory has like a billion plot holes but still???? I think it's interesting to think about. Anyone else have anything to add?