I tend to think of a personal horror, rather than a historical horror such as the Holocaust.
Part of what keeps me sober is the thought that i could wake up in a jail cell, asking what happened, having a police officer tell me that during my "blackout" I committed vehicular manslaughter and took the lives of an innocent family on the road and destroyed the lives of their loved ones.
That's enough horror to think upon to keep me sober.
If you think it would never happen to you, you underestimate the potential alcoholism can do to destroy you.