Now this is interesting - take a look at this test to see which side is your default...
Left Brain vs Right Brain Test
I blame my difficulty in seeing "anti-clockwise" on an abnormally overdeveloped right brain, keeping a left brain down.
(but I also thought it wise to check the gene pool):
Family stats thus far:
Dad: sees both directions (and can change directions "at will")
Mom: sees both directions
Little Sister: only sees clockwise
Little Brother: sees clockwise first, but after reading text, sees counter clockwise ("potentially because language is a left-brained activity")
Moi: mainly sees clockwise, but can force herself into counterclockwise with intense concentration, strain (and cursing)
Older Brother: mainly sees naked lady dancing, but can force himself to see counter clockwise with intense concentration, strain (and cursing)