-That something called "stopping power" actually exists.
-That caliber actually matters when discussing common service/defense pistols.
-That the 30 Carbine is ineffective.
I especially get a kick out of the various versions of this same M1 Carbine story I've heard countless times...
"My ____ served in ____ and while stationed at ____ they were overrun by the _____ .
My _____ grabbed his M1 Carbine and started firing but the _____ soldier would stop charging, even after my _____ emptied the entire magazine into him.
When his M1 Carbine ran dry he pulled out his .45 and fired one shot which instantly dropped the ____ soldier.
After the battle my _____ walked over to a _____ and smashed his M1 Carbine to bits, vowing to never use it again.
He picked up a discarded _____ and fought with that the rest of the war."