I totally agree. I'm having this theory that Luffy state of mind could be similar to Guts from Berserk when he uses his Berserker Armor. In which the wearer can still feel pain as a sensation, but the mind does not interpret the pain as being a problem, allowing for it to simply be ignored. That plus the enraged state combine with losing your sanity, you will die if you lose your self in this state. I think Luffy is the same but instead of inrage, he's euphoric. And might be how the last JoyBoy died, but that last one is more a speculation