IMO - THE most fascinating aspect of bodybuilding is the irrefutable biological fact that some people have the necessary genes to explode in growth to such proportions to see them in contest condition IN PERSON is literally an incredible sight. I love B&A pics of pro bodybuilders because they graphically illustrate the biological fact that its not stupid shit like protein or creatine or drugs or what type of apparatus is used that make a professional bodybuilder its that individual person or group of people have that as of yet unidentifiable genetic makeup which enables them to attain stunning muscular development doing the exact same thing thousands & thousands of other men are also doing. They (pro BB'ers) have that one if a few million genetic response to strength training. Its not drugs or supplements or any other extraneous factor. The same genetic trait that makes pro athletes, pro musicians. pro race car drivers, pro scientists, etc., etc..
A secondary fascinating aspect of bodybuilding is as I alluded to ^ earlier its absolutely impossible to ascertain by simply observing someone just how large/strong they can become. I've seen some literal skeletons w/in 3 yrs double they're bodyweight in lean mass & get freakin HUGE. I've also seen some large/strong dudes pump & juice like crazy for years and never have an impressive physique at all. They don't have the necessary genes. That can't be bought, or learned or injected.