Having structure in your life allows you to worry less about the menial aspects of daily tasks. For example, you don't have to spend time thinking when you are going to do something if you already have a specific time for it. By not wasting any precious brain power on the menial tasks, it opens up space and time to use the brain for higher functionality.
My Two Cents.
~ Danial Goodwin ~
ps - Originally not planned for this post, a great example of this concept being put into practice will come from Google. They do all the menial tasks for their employees, including food, laundry, baby sitting, gym, transportation, and more. This may seem like it costs a lot to have, but if you consider the well-being of the employees (less sick days) and while at work employees can put their full minds onto the work, rather than having any nagging sensation, like what/where to eat, how the kids are doing, or even transportation worries (Google shuttles/buses).