Have you ever wondered why some things you can do on "auto-pilot" or without thinking, while other tasks are mentally draining? Your thoughtful tasks are using your working memory (prefrontal context), while your repetitive, familiar and routine activities are using your basal ganglia, which doesn't require conscious thought.

Prefrontal Cortex and Basal Ganglia
David Rock and Jeffrey Schwartz summarize the prefrontal cortex and basal ganglia in their article, "The Neuroscience of Leadership", in "strategy+business" magazine:

• Prefrontal cortex - working memory, the brain's "holding area," where perceptions and ideas can first be compared to other information. Fatigues easily and can hold only a limited around of information "on line" at any one time. Promotes and supports higher intellectual functions. It's particularly well developed in humans and doesn't exist below the higher primates.
• Basal ganglia - involved by routine, familiar activity. Functions exceedingly well without conscious thought in any routine activity. Any activity conducted repetitively (to the point of a habit) will tend to get pushed down into the basal ganglia. This frees up the processing resources of the prefrontal cortex.

Example
You can relate to this using driving a car as an example. When you first learn to drive a stick shift, it's a lot of thinking and processing. You're using a lot of your working memory (prefrontal cortex.) Once you get enough practice, it becomes a habit and you no longer have to think about your driving. At that point, you've baked the routines into your basal ganglia.

How To Use This
You can apply this in three ways: First, when you're learning something new, chunk it up so your working memory can handle it. Second, when you are getting overloaded, consider creating a checklist so you can "dump" your working memory. Third, when you are learning a new task and it feels awkward, rather than get frustrated, remind yourself that you're dealing with prefrontal cortex and you haven't move it to your basal ganglia yet.