When is it appropriate to use the F-word?

The top 10 times in history when using the "F-word" was appropriate:

10. "What the F was that?" - Mayor of Hiroshima, 1945
9. "Where did all these F'ing Indians come from?" Custer, 1876
8. "Any F'ing idiot could understand that." - Einstein, 1938
7. "It does SO F'ing look like her!" - Picasso, 1926
6. "How the F did you work that out?" - Pythagoras, 126 BC
5. "You want WHAT on the F'ing ceiling?" - Michelangelo, 1566
4. "I don't suppose it's gonna F'ing rain." - Joan of Arc, 1434
3. "Scattered F'ing showers...my ass!" - Noah, 314 BC
2. "I need this parade like I need a F'ing hole in my head!" - JFK, 1963

And #1.....
"Aw c'mon, Monica, who the F is going to find out?" - Bill Clinton, 1997