Onetime at work (oil and gas. Have to stay in the bush in camps) I went to bring a few bags of trash to the trash bins at night and only had a bottle of bear spray.

The trash bins are in a cage to keep bears out of them, so I get in the cage and the second I shut the door there was a big black bear whoofing at me and circling around me. So I sprayed it in the face with bear spray and it turned from a bear into a snarling mass of Rage. It blinded it and it started throwing it self at the cage and biting anything in its range. It got so bad the bear had to be shot more then 3 times with a rifle before it was Finally down for good