I've had lots of reasons why we can't get the jet bridge to the aircraft - 'we appear to have surprised the ground staff with our arrival' being one often used flight deck announcement, or we simply can't get on stand to access the jet bridge - the most recent reason being that there was a vehicle broken down on the stand, seemed to be beyond the wit of man to move it for more than 25 minutes, but broken jet bridges, not that often.... as said above, maybe a couple of times a year.