I don't keep a fully stocked "bug out bag." If things got bad enough where I wanted to get out of my current location, I'd rather take some time to plan and look for a safe place to go. Then again, if things got that bad, we have more problems than just where to go.
On the other hand, I do keep a fair amount of stuff with me most of the time: keys to the house and other important things, car keys, small (and bright) AAA flashlight, small multi-tool, wallet with IDs / cards / cash, smart phone, etc. My work bag has my laptop, charger, various USB cables, small umbrella, disposible poncho, small first-aid kit, a few extra batteries, a small flashlight, and some other goodies. It's not meant to help me survive the apocalypse; it's designed to make a shitty situation less shitty.
Each of our vehicles have roadside emergency / stranded gear in them: a few disposable ponchos, emergency space blankets, jumper cables, flashlights, small socket set, a few screw drivers / pliers / other tools, glow sticks for illuminating a car with a dead battery or ourselves if we get stuck walking, hooded jacket, some junk clothes, a tarp, a bit of rope, duct tape, etc.
Between all of that, it would take a very major disaster to require something that we don't have or can't easily get. And, chances are, we wouldn't be able to get to a "bug out bag" in time if a major disaster did strike.