He's not a complex individual, plus he's the main character, so we pretty much know everything we need to know by that point.
What are you trying to get here anyway?
Eh, I think the guy you're replying to made it confusing. He/she was quoted your comment as if to say "this" and added a question to it since he is wondering what it has to do with anything... I think.
OT; Luffy doesn't hide his feelings. You know what he means because he says it. He isn't a 'I will say one thing but I am thinking another' kind of guy.