When did you last forget to brush your teeth? My guess is that is is not something you forget unless something extraordinary is happening (or you have no teeth....). It's good to have a routine to handle teeth-brushing (and other aspects of getting up) so that you don't have to expend much mental energy on them.
At work, routine has a bad reputation. The lack of expenditure of mental energy can backfire. We think of the weekly meeting that is too often a waste of time - it happens out of habit rather than because it has any useful purpose this week. We think of routine as boring and repetitive and want our lives to be full of varied and exciting tasks every day ... at least until we have to manage the resulting workload.
I was thinking about this because I've found myself getting into the habit of putting a lot of repeating tasks on my to-do list. That works OK, but leaves me needing to expend a bit of mental energy deciding when to fit them around the rest of the day's tasks (or week's tasks). It also makes for a tediously long to-do list, which isn't so nice to look at when feeling busy :-).
Maybe I need to think about some of this stuff the other way around, and make more use of routine to clear the regular tasks. It seems odd, because typically they are less important than the rest of the weeks work. So one would think that the thing to do was put them in the to-do list at low priority so as to fit them around the variable stuff. But possibly the benefits of not needing to think about routine items outweigh the theoretical benefits of making more prioritization decisions.