I recently spent 9 days up at The Expanding Light retreat in Ananda Village for Meditation Teacher Training. The course is intense, but an overall fantastic experience. Savitri and Diksha are excellent teachers, and made the whole thing very enjoyable.
Each day starts with getting up around 6:00, and going to the first 2-hour sadhana session of the day - energization exercises, yoga postures, and meditation. (Or, in my case, going over to Hansa temple for the community group meditation.) Then there's an hour for breakfast, and a couple hours for class, and that rounds off the morning. There's a short noon meditation, and then lunch break. In the afternoon we have two more hours of classes, and the second sadhana of the day before dinner. After dinner we'd have another class most nights, leaving us maybe an hour or so before bed to keep up with the course reading. A couple evenings were "free" time, which mostly meant doing reading, working on the written assignment, and preparing for presentations and student teaching. So it was a pretty full schedule.
What I found, though, was that once I got into the flow of it, I was able to stay in "always-on" mode pretty much all the time. I can't remember the last time I'd been so completely focused for such a long time, and it was an amazing experience. There was a really good illustration of that on the penultimate evening. I had a couple free hours to work on my final presentation, to be given first thing the next day, so I was doing that. Then my neighbor came by to talk to me about her presentation, and to run various ideas by me. I was able to just completely switch modes and focus on her, and then go directly back to working on my own project afterward. No transition time, no frustration, no wasted energy, no nothing. Just being right in the moment with whatever I was doing at the time. It was great to get to practice that so clearly.
Another amusing little bit for me was my morning walks over to Hansa. Getting there by 6:30 meant it was still dark, and I didn't have a flashlight. That made it tricky at first to find and follow the trail through the little section of woods I had to traverse. But though the trail was indistinguishable visually from the rest of the forest floor, I found that I could hear it as I went along. My feet crunched on more fallen leaves when I strayed off the trail than when I was on it. Of course, once I'd done it the first time, it wasn't as tricky, but I was amused at following a trail by ear, nonetheless.