"There seems to be something about him that never grew up."
Fred, I could say that about myself too, and almost everybody I have ever known. :-) (with a very few rare exceptions) Most people live their whole lives without ever dragging most of their old childhood skeletons out of the closet and growing up in the process. They just gloss it over as best they can. They go through the superficial outer motions of being adults, but they're scared inside. And not just a little scared, either! How they show that fear can vary from passive to aggressive, unconfident to superficially confident...but largely unloving. You can't love very well when you're deep in fear.
The ones who are most afraid will never admit to it. Not ever. Such people can sure be a pain, because they will run roughshod over you and everybody else just to have another chance to prove how tough and self-reliant they are. Always somethin' to prove...never miss a chance to let everyone know, "Hey, I'm allright, Jack, but you're just a bunch of pathetic wusses..."
Watch out for such people. They like power over others. They hunger for control. They seek what they do not have, and they can't find it, but they do tend, like scum, to reach "the top" in a competitive society.