When my wife and I visited Banff & Jasper back before the pandemic we encountered a park ranger at a trailhead that was enforcing a requirement that hiking groups be a minimum of three people since a black bear was known to be in the area. They apparently felt 3+ hikers in a group would make enough noise to dissuade bears from approaching.

We were also told of a bear that they had recently been forced to euthanize. They had determined that the bear had either been deliberately fed by a hiker with a backpack or had seen a backpacker drop some food. Whatever the case, the bear had associated backpackers with food and would accost almost every backpacker it saw. If you didn’t have a backpack it would leave you alone… Apparently once a bear learns about a food source it will always remember it. The park rangers had tried everything they could think of to discourage the bear, from bear spray (mace) to beanbag guns to tranquilizing it & relocating it. But it kept returning to the area and approaching backpackers, so they eventually had to put it down.

Grizzlies aren't that chill. They'll bluff charge you. I mean it's still pretty chill in a way I guess, but as someone on the other end of that charge, chill might not be the word you choose to use.

Based on how they evolved, I'm gonna assume that occasional aggression is pretty normal, just like with any other animal