"I don't think it's possible to adequately prepare for a bear attack..."

I agree that with bears being unpredictable it is difficult to prepare for an anticipated moment in a bad situation and to thereby have a sure way out of injury, but preparation would consist of be aware of the possibility of a curious or hungry bear becoming aggresive, not leaving food scents nearby, having AT LEAST a pepperspray device, and even a first aid kit. There are many things one can do to adequately prepare for bears, although there is no guarantee that even the best equipment will not fail you despite your skill level with them.