In a pub in real life can get you poked in the nose, so I rarely use real life examples for the internet as they have real life results. Most keyboard warriors stay at their keyboard and don't bother to come into your internet space such as your job or stalk your social sites. You are absolutely right about pubs and such.
But I could of been more concise and also wrote "after correcting troll over and over and over", we still can get drawn in. My rare real life example could be the shoving and pushing siblings who take turns pushing each harder and harder each time until one of them goes through the screen door. Real life has consequences, where keyboard assholes don't think they're doing any harm. They can and do.