The last two times we played OD&D, my players asked when we'd play Traveller again. I wasn't ready, as I've been fully immersed in my OD&D world for a long time, but suddenly I find myself back in the Star Clans universe. During our last Star Clans session, the characters misjumped to an empty hex far from home, and were out of fuel as we ended the session. Part of the reason we haven't played for six months was because I wasn't sure what would happen next. I don't tend to plan things out in my game worlds; random events occur because of die rolls during play, and between sessions, I won't give things much thought until something big jumps into my head, 90% complete.
That happened twice in the last two weeks with Traveller. I knew exactly what to write up for the next session... until two days ago, when the first scenario was completely replaced! Now it's just a matter of jotting down some notes and scheduling the next game!
Am I the only DM/Referee who "discovers" his world rather than creating it?