The speaker says that a high-dimensional function constant almost everywhere can be much easier to fit than a two-dimensional, highly varying function resembling a heartbeat monitor.

“dimension free bound, it depends on kind of the the frequencies of the target function you're fitting. And kind of intuitive like once you think about this actually also makes sense. Like if you have a high dimensional function which is constant almost everywhere and uh then it's much much easier to fit if you have a like two dimensional function which looks like a heartbeat monitor.”