Dang! Ever since I was snuck up on by a polar bear when I was a zookeeper, there was a fence between us, but imagine turning back to its enclosure, yer face maybe 8-10" from the fence only to have your entire field of view filled with white fur, then looking up to see the bear with its front paws at the top of the10' fence, it looking down with a " this close to lunch, monkey, this close" look on its bear face, I've had a deep respect for bears, what they can do, and just how sneaky they can be when they put their minds to it! Nearly had a heart attack right there! It crossed its rear enclosure silently in about 2-3 seconds over 50-85'!!
But a big black bear could mess a fella up too! I've ran into them in the foothills of the San Gabriel mtns, and a couple of those I steered wide of to be sure!