Try to imagine a line like this happening on Barney:
Grover, in what is a recurring feature, has just shown us a short video about another culture, here kids in the Philippines playing in a park. When the video finishes, we see that Grover is at the top of a slide, just like the kids were in one part of the video. The videos are usually more culturally illuminating than this one was - we usually see kids making things specific to their culture, or dancing native dances, or whatnot; here we just saw the kids playing in a park. So, Grover says, "Well, so that wasn't educational per se." Try to imagine Barney saying "per se." You can't. And that's one of the things Sesame Street has always done so well - not talked down to kids. No, my toddlers don't know what per se means. But, thanks to Grover, they will sooner than they might have otherwise.
Oh - and before going down the slide, Grover says, "Top of the slide, ma!" Tell me that ain't just a bit of genius.