In the supermarket, an auntie was squeezing tomatoes.

She squeezed each one and then put it down.
The uncle next to her couldn't stand it anymore: "How can others buy if you've already squeezed them?"
The auntie didn't even lift her head: "If I don't squeeze, how do I know if they're good or not?"
The uncle said: "You squeeze and then you know? Are you a tomato detector?"
The auntie finally looked up: "I've been eating tomatoes for sixty years, my hand is a detector.
If you don't believe me, then buy some rotten ones and don't cry."