Well John, first, let me say that that "1943 London hospital" line of yours cracks me up every time I see it around here. Yes, I always find it extremely "humorous"!(notice the lack of that...well, YOU know)
And secondly, though I've also now checked the web in an attempt to find the origins of that "Feeling a little Paranoid, Jimmy" line, I too have failed to find it anywhere. However, I'm not exactly sure if Mr. Nicholson was in fact the actor who mouthed those words. But, I DID however find this website during my search which shows many of his more famous lines.
http://www.destinationhollywood.com/celebrities/jacknicholson/famouslines_content.shtml(I have to also however mention that this list probably isn't a complete list, as there is absolutely NO mention of the line in "Five Easy Pieces" where Jack advises the waitress at the truck stop of what he thinks she should do with any leftover chicken salad on his food order!!!)
