Why does this irk me so?

I see it all the time. Just last night I watched some kid do shrugs in the power rack with a 25 pound plate on each side, yes, just one plate on each side.

I've also seen the curl guys doing exactly what you described as they watch themself in the mirror.

I try to be polite and leave people alone, but I love to go set up next to these kids and just embarrass them, and then walk away.

That's why I train at home in my power rack and platform in the corner of my basement.  If I trained at a commercial gym and a mullet in spandex started to tell me that pulls and squats were bad for my back again I was going to invoke "The Power of Greyskull" on them.  Thus to avoid my hometown's finest, I needed to train at home.  There are some great heavy duty gyms but unfortunately they are hard to find. 

I love to train when the gym is crowded.  I love the energy.  I just go over and ask to work in.  They either have one more set and move out, or we start loading the bar for my set.  I try to make them stay and do more weight and sets, but most times they split. 

These are the reasons I invested so much money into training in my dungeon. And I continue to buy more weight every year. I miss the gym sometimes but I don’t miss the guy in the corner looking at himself in the mirror and his legs are the size of 12 year old because he never works legs, but some how finds time to do curls everyday on the power rack.

Obv.  But it was legal then.

He has calves like Zolk.

He-Man is really Conan, so he "may have dabbled" in the struce if based on Arnold .  From Wikipedia...

Originally, the He-Man action figures were designed as a toyline for the Conan The Barbarian movie. However, due to the sex and violence of the film, the idea of marketting a toyline for children based on such an adult film was scrapped.^{[citation needed]}

The toys that had already been put into production were changed and combined with the ideas of Ray Wagner.^{[citation needed]}

In 1980, Ray Wagner, Mattel President US, requested that Mattel's preliminary designers come up with a proprietary male action line for the company. The reason for doing so was that Mattel would not have to pay royalties to an outside source.

I cant believe an ex Brownie would do such thing.    

Thats Why I'm a Cowboys Fan