Innocent Vacation

Listen, you're clearly not the sharpest tool in the shed if you find this funny. You see, 'hit it with your best shot' is a reference to the 9/11 terrorist attack on the World Trade Center in New York, which is often referred to as the Twin Towers. It's a dark joke because it makes light of a serious tragedy. You know... lots of people died and stuff... The joke plays on the double meaning of the phrase 'hit it with your best shot', suggesting a plane crashing into a building.