One of The Beatles’ most famous songs was inspired by the sister of Mia Farrow.

In 1968, the Beatles traveled to India to study Transcendental Meditation with Maharishi Mahesh Yogi. Also staying at the retreat was Prudence Farrow, Mia Farrow’s younger sister.

According to people at the retreat, Prudence became so intensely focused on meditation that she spent days isolated in her room, rarely coming outside. John Lennon eventually wrote a song encouraging her to rejoin everyone.

That song became “Dear Prudence.”

The famous lyric:

“Dear Prudence, won’t you come out to play?”

was quite literal.

Prudence Farrow later confirmed the story herself, and she is still alive today.