I have a few variants of this; the funny thing is, that until you mentioned it, I never thought much about it being unusual before.
Whenever I arrive at home or work, I have to spend some time walking around, getting my bearings. If someone interrupts me before I have had a chance to do so, I feel very uncomfortable, and I start forgetting what I am there to do.
Also, I will walk around and around a room if I am thinking. It drives my husband crazy, so I usually try to close the door behind me to be alone. As a child, the first thing I had to do on arriving home from school was run around and around the backyard (trailed by our dog).
Animals frequently pace or circle their territory; dogs will circle several times before laying down. I think it may be a residual behavior that served a purpose for humans in the past, and continues to be a comforting or relaxing stim to those of us who are generally a little more anxious about our environment. Also, if I recall correctly, it is linked to thinking processes because the movement stimulates the parietal lobes of the brain.