It really makes my blood boil when I travel as pax and sit next to people ignoring safety briefings. Recently I flew back from Brussels and as a matter of course always count the number of rows between me and the exit. The guy next to me thought was mad and found it funny, so I explained to him if we has a fire on the ground and had to evacuate, I would know exactly how many rows I would have to crawl on the floor till I got to the exit. I also suggested that he not try to grab on to any of my clothing in this event as I would be more concerned of getting out of a smoke filled aircraft.
He watched the safety briefing, even turned his Laptop off and Blackberry as well.
I fly the 737 both Classic and NG and know the door exit opening by heart, but I always read the card and listen to the briefing, just in case.
I hope that those of you that know better than me are never between me and a door on that day, as I will go over you.