I'm not actually sure that I do. The title is just the name of a song my brother made up and sang a lot when we were kids.
I have the jeans. I tried them on with half chaps, and they fit fine. They look like well, jeans with half chaps. I'm almost wishing I had fuller legs, so that the jeans looked more breech-like. I mean, I don't wish I was flabbier, but I do wish I looked more suave, I guess. Sigh. I'm not really a looks-oriented person, but I do love traditional turnout, which jeans are not. That said, they are comfy, and if I decide I hate riding in them, they'll be fine for hunting and hiking and whatever else.
I'm currently coveting some full seat breeches to see if they ride and wear better, but it's definitely not in my budget for a while now. In the mean time, check out this movie preview that a friend sent me: If Horses Could Speak . I have not watched it with sound on, so you're on your own if you're a work. It's subtitled, so it's ok.
I don't ride at a level (or barn) where hyperflexion is common or practiced or even really seen. I've withheld any judgment on the topic because I simply haven't been able to the the research, and I've mentioned before that I don't think "No way vs Yeah huh" is really an argument worth listening to. Still, this has promise. I hope to see the full length movie.