Paranoia 2nd Edition rulebook, p.104, under the heading "...And More". That's where I found my muse.
I've embraced brainstorming as a creative technique, and I do it this way: I decide on a topic and start throwing crap at the page to see what sticks. No idea is too dumb; if i think of it, I write it down. Pump it out, clear the channel for other, better ideas. Plus, who knows? An idea that looks dumb now might spark the development of a BITCHIN' one later. Hey, it's happened.
So -- the Paranoia connection. There's a section in that old rulebook that's about making up your own adventures, and it gives you lots of scenario ideas. After listing a series of bare-bones adventures, the section closes out with the aforementioned "...And More" header, which is followed by a short list of one-sentence game-sparking ideas. The first item is Conan shows up looking for a fight.
Somehow, it has become a ritual for me to list that as my first complication, situation, goal or what-have-you when I start throwin' stuff down, regardless of game setting and genre. Dunno why; maybe I just think it's funny.
Or maybe it's just to remind myself that anything, no matter how simple it may appear at first, can be fun.