i am afraid of revolving doors.

update: while the theories and delving into people's fears were interesting, my fear of revolving doors is this:

i am afraid that my last foot out the door (usually my right because although i'm right-handed i've got touches of ambidextrousness, and i lead with my left foot) will get caught in the door and that there will be enough pressure to shatter my 2 ankle bones. because of the physics involved, these bones are unlikely to shatter, but it's an irrational fear.

sort of like my fear of falling down stairs. that's not so irrational though, i usually take a header down the stairs somewhat spectacularly and in public once a year or so.