This is funny this has come up, this past spring I was in 12C and that curtain was pushed back from the gentleman in 4C, and I knew I can’t simply push it into the back of his head, so when he did move up for his drink I did push it forward, but behind the part of the seat that supports the back of your head. It however moved again and the gentleman may have been a cowboy and kept moving back and forth, up and down so much I was watching my movies in 3D. I ended up sliding it to the left as no one was in 12B and it stayed there for the rest of the flight. When we landed I noticed the gentleman did not look like a cowboy so I figured Hemorrhages?