Youngest Daughter:  “Clark Kent?  Didn’t Clark Kent write all those books under the name of Mark Twain?”
Dad:  “Did Ben Franklin invent the toilet?”
Oldest Daughter: “No, that was Leonardo diCaprio.”
Dad, explaining ancient comedians to the kids:  “George Burns played vaudeville.”
Son:  “Who’s Vaudeville?”
Piano teacher:  "Robert Schumann was born in 1810."
Youngest Daughter:  "Oh!  That's when my mommy was alive!"