大統領がパズルする

英語のジョークです。

まずは読んでみてください。

The Vice President of The United States walked into the Oval Office in the White House.  There he saw the President yelling and screaming like a madman.“What’s the matter, Mr. President?”

“Not a damn thing,” the President said. “I just finished this jigsaw puzzle in record time, that’s all.”
　
The President smiled from ear to ear.

“Well, that’s great! How long did it take you?”
　
“The box said 3 to 5 years, but I did it in a month!“

笑えるんです(^^♪　ポイントは最後の　"The box said 3 to 5 years" の意味が分かればツボります。どういう意味なんでしょうね？動画を見てご理解できたかな？