Believe you me, I was very confused the first time I heard the figure of speech "believe you me." I've noticed that older people use it a lot. Is it from a film, a song, or was is just a fashionable figure of speech (like "24/7")?
Believe you me comes from old English. It originated from someone getting excited trying to say believe me, in turn saying believe you me. If that is what he really said or was what the other individual thought that is what was said, we will never know. Then it just caught on.
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