About 20 years back, I was running a small campaign. I had been running a large campaign, but a near-TPK in A1-4 took out more than half of the PCs and half or more of the players. Two guys held on to keep gaming, one of whom still plays in my game and one of whom drops in occasionally to join us as a guest star or for a short session (he played Caveman in Gamma Terra).
One thing about that game was that we'd play every day. We all had jobs, but when my two players would get off of work they'd come over and we'd play for a few hours. Every night.
When a blizzard came and shut down the state, and the roads were closed, they got their boots on and walked across town to game.
But as you might imagine, playing every day meant a lot of GM work. Basically I'd go to work in the morning, keep stirring over material in my head as I fiddled with statistics and so on for my day job, and then I'd write furiously on lunch. Then I'd go home, eat, and then run game.
Repeat day after day for weeks on end.
What made this interesting for me was that I didn't have time to sandbox the game. I couldn't write for all possibilities. But I didn't want to give the PCs no choices - although the situation then ended up in (drafted into a military campaign) meant I could at least partly determine the path. What I was able to do was decide in advance what was almost certainly the way they were going to go. Like perhaps jamming in music, or when you get that flow in a martial arts competition or practice, I just knew where they were going to go. I could lay out choices and then write to the choice I knew the players would make based on their PC's personalities and their goals. I was in a groove. The choices were real and legitimate, it's just that I knew which one they'd choose so I could detail that one and let the others slide.
I didn't know what would happen after the choice was made - lots of dice to be rolled, combats to be had, clever player actions to adjudicate. But I could stay a step ahead.
I kept that groove going until the game ended when the PCs made a succession of bad choices and ended up with a religious geas and the players decided it was time to start over.
Incidentally, it's the first time that this mini showed up and kicked butt.
These days, I've got enough of a luxury of time that I can stock an area and see how they go, but then, it was all knowing the situation, and being in a groove of knowing where my players would go. But I miss that feeling of perfect sync.
Have you ever been in a similar situation? Writing just ahead of the PCs, on a daily or near-daily basis, yet still legitimately giving people a choice? It's one of those times where everything was flowing. Have you had that?