"Always go to other people's funerals, or they won't go to yours."
It's funny because dead people don't go to funerals. (We won't discuss ghosts or spirits.)
"Baseball is 90 percent mental. The other half is physical."
It's funny because 90 and 50 add up to 140. A percentage is out of 100, so the other 10 percent would be physical. A half is 50 percent.
"You can observe a lot just by watching."
It's funny because to observe something, you watch it. You may take notes, but the main part is watching.
"It's deja vu all over again."
It's funny because deja vu means that it seems something being experienced seems like it already happened or did happen. Saying that again means it happened at least two times before the current time. It works in that situation, but it's probably not what Yogi Berra meant.
"If people don't want to come out to the park, nobody's gonna stop them."
It's funny because people don't need to be stopped when they aren't going anywhere. What Yogi Berra probably meant to say was "If people don't want to come out to the park, nobody can make them come."
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