I've had close encounters with a few black bears and cougars, but they are hunted here in NM, so they tend to run away. The only bear that didn't run was in my tent (Luckily I wasn't). In those days I locked my rifle in the truck because I'd never seen a bear. She had no fear of humans, when I yelled at her, she just stood up. A warning shot made her leave for about 5 minutes. The second shot wasn't a warning shot. I came across a lion on an elk carcass and it growled at me and looked ready to defend it's meal. I walked away.
Once a bear found my elk before I did. It left before I got there, but I was glad to have my .357 with me, and spent a lot of time looking over my shoulder. I had a cougar watch me clean my deer once. I didn't notice until it got dark, and my headlight lit up his eyes.
When bears come to the sound of a shot, they aren't hunted enough. I'm glad I don't hunt in grizzly country, but those idiot environmentalists want to reintroduce them. Google wolf attacks in the 19th century, and it will scare you.