Luke being unhappy is definitely the exception nowadays.. He is a very happy baby that gets a lot of enjoyment from looking at peoples faces. If you smile at him you are typically gifted with a smile right back. His smile is kind of sly, like he knows something about you but isn't telling. Other times it is a full on toothless goofy grin. Once you get your first smile out of him you just keep going back for more.
The other aspect of his personality I can make out is that he isn't a big fan of being held. Sometimes he likes it and other times he doesn't. The only way he tells you that he doesn't want to be held is that he gets real squirmy and no position seems to do the trick. Placing him on his back or tummy seems to make him happy when nothing else does. If he does need to be held like when outdoors sitting him in your lap looking out yields good results. I think Luke is interested in the world and wants to see all of it. I think that sitting in your arms looking at the ceiling or your shoulder just doesn't cut it for him.
I think Luke is going to be an early mover. I don't think staying in one place will do it for him especially when he has a role model in his little sister. I think he will be a happy person who will get a lot of enjoyment from others. He is too young to show any signs of shyness that his sister possesses. But considering both Mom and I are a bit shy I kind of expect him to follow the same path.