What gets me is that in a world where artists often experiment with viewer interactivity, sometimes you just can't tell what in a museum you're supposed to touch and what you're not supposed to touch.

There was a huge retrospective exhibition of Yoko Ono's work at Musee d'Art Contemporain in Lyon, France in 2016. Included were a mixture of interactive/participatory elements (ladders you were meant to climb, a room filled with hammers and nails that you were supposed to contribute to by banging a nail into whatever you wanted) and other obviously not interactive elements (videos, paintings, things protected by glass).

And I remember, in the same room as the ladders you could climb and combat helmets suspended from the ceiling by ropes that were swinging around because people were walking through them, was a sheet of either canvas or paper mounted on the wall, with another piece of either canvas or paper suspended about an inch in front of it by some string, with some holes cut into the front sheet so that you could just see that there was something drawn or written on the hidden layer.

Well, in a room filled with people talking and laughing and climbing ladders and pushing helmets around, I went to peek behind the curtain and lifted up the front layer to take a look at the one behind.

A custodian ran at me and told me to step away. I still don't know if I damaged it or participated in it.