Had the misfortune of flying AMS-JFK on KLM and this woman behind me thought it was appropriate to first jab me in the side (by sticking her hand through the seats) and then slapping me on the head because she was unhappy about my reclined seat (I was in a middle seat because of a KLM ooops-we-lost-your-seat-sorry-hoor moment) I was very happy to tell her in three languages that if she touched me again, I'd rip off her fingers. I don't think she understood any of it, but I imagine she got the jist from my tone.

Coach is uncomfortable, it gets 2% more comfortable when your seat is reclined. The person behind you doesn't have anything to say about it.