The most dangerous chemical in the world

Silas will be five next week. What is it with five that makes an adorable, sweet little tyke turn into a fit throwing, door slamming, pseudo-swearing little tyrant? After being made to finish his chores (which involved much wailing and gnashing of teeth), I went with him up (it's all up here on the mountain) to his swingset. He's recently learned to swing under his own power and, as with any new skill, wants to do it constantly. Since it's just not as much fun without an appreciative audience, I must go along and provide a running commentary about height achieved, speed reached, and how no one else, EVAR, in the history of the world has swung so high or so fast.
We have cushioned the playground with a very thick layer of finely shredded mulch. When he tumbles from the overhead ladder (and he will), we prefer he land on some cushioning. Because his parents are owners of real excavating equipment (loaders, backhoes, dozers, etc), Silas is the proud possessor of quite a fleet of Tonka dump trucks and equipment. Bear with me, I'm going somewhere with all of this drivel, I promise.
Anydigger, after the swing session is over, he starts to play with his loader and dumptruck. He's happily scooping mulch, hauling it around a little road he's carved and dumping it in the truck. He asks if I'll play with him. Um, no. No, I won't. Firstly, mama don't do crawling around in the wet mulch. Secondly, who would hold my coffee? Thirdly, it's hot, buggy and I'm outside. That's all your getting. So I tell him that I'm the supervisor. That I'm here to make sure he does his work right and to make sure he doesn't slack off. He scoops two more times, looks at me and says "you gonna pretend you a mister? Misters gotta be the bosses."
What?the?fuck??? Did my son, who has spent his ENTIRE life being hauled around to construction sites by his mother, (who is the boss) just tell me that the bosses had to be misters? Where did this notion come from? How did it get into his head? He doesn't watch television other than Spongebob (because I like it, shut up) and I don't read him fairytales where the prince saves the damsel and I even explained that Mary Jane is a useless waste of skin because all she does is sit around and WAH WAH WAH Save me Spidey and still, he has this notion.
He doesn't watch violent movies yet he will take a stick and wage war with it, whether it be a sword, a rifle, or, in one particularly imaginative instance, tied a balloon to it and made a mace. He will take his dolls, or "action figures" which are dolls for boys but good lord don't call them that, and they will beat the hell out of each other. This from a child who has never been struck in his life. Nor has he ever seen anyone struck. This violence, this hardness, this boyness. It's the testosterone. The cause of world wars, schoolyard fights and everything in between. The most dangerous chemical in the world.