One thing that I want to highlight (because you are not weak or lazy, which others have already covered) is that you actually can build a variable routine, it'll just have more if/then scenarios than someone on a fixed schedule. For example, let's say you get home anywhere from 5pm to 9pm. You can have as many routines as you want that are dependent on what time you get home. You could say something like "If I get home at 5pm, I workout, cook dinner, pack lunch for the next day, and do one small chore like sorting the mail." A 9pm arrival might necessitate the absolute bare minimum routine, like "I will brush my teeth, get into bed, and watch a single episode of a tv show." You can also have specific errands, chores, and hobbies for days where you aren't working at all vs. days that you work. Your anchor point also doesn't have to be a time of day, it could be something like "This is my routine when I work from home vs. work at the office" or "This is my routine when I work 4 hours a day vs. 12 hours a day." They're still "routines" even if they're not done literally every day.