I am perpetually shocked that a structure (hair) that we can actually see is so close to nanoscale.
(It's also noteworthy that our sense of touch in fact extends into the nanoscale: https://www.nature.com/articles/srep02617)
Which is pretty shocking when you realize a nanometer will hold about 10 hydrogen atoms (give or take the fact that the electron cloud repulsion isn't well defined), meaning you're in fact only talking about 5000 hydrogen atoms at the same packing for that 500 nm linear distance.
Which puts the idea of "Plenty of space at the bottom" by Feynmann in an odd contrast because it's like...well, that doesn't seem so far away when my basic eyeball and some optics can operate plausibly see down to that scale directly - photons are interacting with things and passing straight to it.
An atomic force microscope is even more direct - while not absolutely "atomic" - you can definitely with a sharp enough tip push things around on the nanoscale.
The problem is definitely as you note: things do in fact behave very differently when you're doing that.