I think black bears aren't generally scared of humans, unless you do something scary towards them, or you startle them by appearing suddenly when they though they were alone. They are mostly aloof and don't care, so long as you're being casual, even when you're pretty close to them. But if they sense any aggression from you, then yes, it is very easy to scare them. Here's a lady in the woods with a black bear demonstrating how much black bears dgaf when the human is calm: https://www.youtube.com/watch?v=Bkwy0scRXBU . Warning: video includes a political endorsement which might annoy some people, so if that might be you, stop watching around 1:13

Also, maybe that video has more issues than just that. What she calls "a bluff charge", I'm not enough of an expert to say she's wrong. But I have seen bluff charges that are way faster and pants-shittingly scary than that. And I'd sort of expect any bluff charge to come from a bear who is freaked out enough that he's going to skedaddle as soon as he breaks off of the bluff charge. But I'm not an expert and maybe somebody will correct me here.