Cerebellum

Q.  Sometimes I don't remember doing routine motor tasks.  Am I losing my mind?

A.  Movements that are practiced over and over become automatic.  The cerebellum completes the task without conscience effort therefore you are not "aware" that the task was completed.

The cerebellum is involved in the coordination of voluntary motor movement, balance and equilibrium and muscle tone.

"If you ever learned to drive a car, play the piano, or touch type, you probably remember what a long, laborious process it was and how many hours of practice it took to become proficient.  If you still do any one of these today, it is likely that you do it so unconsciously you would have difficulty telling someone how you do it.  You can thank your cerebellum for this ability."