A Happy Idiot? Essentially an Optimist by nature? Not a bad choice. You might be wrong lots of the time, but being wrong wouldn't necessarily bum you out. You'd just carry on, with a smile on your face.
Maybe you'd often be "bemused," a confused, puzzled, "tolerant" amusement, but you'd also often be genuinely "amused," you'd find a light, gentle and pleasant way to entertain yourself and others.
You wouldn't be a wise-guy. You'd be sort of sunny, and goofy, and always look for a silver-lining. You'd be sort of silly, and sometimes even simple-minded. You'd choose simple-mindedness, because it's a little easier, and useful. You'd find your head less cluttered.
You could think of big subjects, look at the big picture, but it would be just another form of entertainment. You'd discover all kinds of activities that made you laugh, and admit you really didn't know what you were doing.
But the doing would be sort of fun, diverting, and in a weird way, unexplainable to yourself, amusing.