I have a buddy who had a black bear sow with cubs charge his tent several times while he was in it. (From her perspective, it was just something that looked, smelled and maybe sounded out of place.) My buddy could see her through the bug netting, but she probably couldn't see him. He was armed with a Ruger SP101, but he decided he wasn't going to shoot unless/until she got to the tent. He knew .357 out of a short barrel probably wouldn't do the job anyway. After a few bluffs (he remembers exactly how many), she lost interest and led her cubs away. He now carries a Smith & Wesson 629 in the back country.
I've never experienced anything like that, and still don't sweat it. However, I own a bear can and use it and cook, eat, do dishes and store food and mess gear away from my tent. Better safe than sorry.