The next 6 weeks will not be fun - especially for my wife. Whenever I've had such marathons, she's observed that I get too consumed with the projects and leave nothing for her and the marriage (and rightly so). So I am treading carefully this time, both to make sure I am fully present at home and to lay a framework for how I will handle future marathons, if needed, without letting the marriage dynamic suffer. I'm all about experimentation to learn new ways of doing things.
So what actually happens during these marathons? Programming a ton. Little sleep. Junk food. All-nighters. No social life. No exercise. No TV shows. No drum practice. Background music all the time. Coffee. Heavily-chalked blackboard with visualizations of various ideas. Odd sleep hours. Any moment you don't have to be anywhere else, you spend working on the program. Non-stop. It's not fun, but I always get a ton of work done. This little habit saw me through college. I'm one of those guys that could do two all-nighters before the final exam and still pass the class having not attended most of it throughout the semester. In six weeks, we'll know whether I still got the mojo.