The real reason schedules help is an indirect consequence: the ability they have to make us feel present.
Think about times where you feel a bit lost in what you are doing. Maybe things are tough at work; the load is piling up and you don’t even know where to start. You feel yourself getting hot under the collar, as everyone around you seems to be getting on so well and simply. You’re at a point where you can’t even think about what the problem is, just the overwhelming sense of having a problem.