Between @AlphaVictor writing his article on room acoustics, and having visited 2 amazing ones in the last few weeks, I stumbled across this wonderfully put together video by John Storyk, going through tons of real world examples, but also going a little deeper than some people get to in some of the shorter interviews we see these days.
Man, if you don’t even understand this stuff, its still so much fun to skim through there (yes, I know its really long), find any spot, and just appreciate how much guys like him (there’s only a small handful in the U.S.) really know about this stuff. This guy has a superb way of presenting it.
Not placing this video here to ‘compete’ with @AlphaVictor’s, rather to add to it! 
, right now I am working on making gifs so I can explain the calculations of room modes a bit better geometrically rather than the mode formula cheat sheet.