This is a slight distortion, or even a merging of two linked ideas and
exhortations. The original advice and the common suggestion is "
lie back and think of England".
Allegedly,
Queen Victoria gave this instruction to her daughter on her
wedding night, but it's more usually thought of as a general suggestion to new
upper class Victorian brides who were brought up in
ignorance and
innocence and were not expected to have a clue about the delights of the bridal suite in their
pretty little heads.
The supplement
encouragement is
"Whatever happens, remember it happened to the Queen."
As in, "It may be disgusting, but it's perfectly normal. Just relax. The world won't end. Really, darling. Look, the Queen did it at least several times, so it's definitely the thing to do. Honest. Sorry we didn't tell you the details, but, buck up old thing."
This was intended as
reassurance for times of
surprise and trial, though thinking of the Queen (whether
Elizabeth or
Victoria) at any moment is a guaranteed
passion-killer. i doubt it inspired many.
The best use of the phrase has to be in a
Billy Bragg's song "
Greetings to the New Brunette":
How can you lie back and think of England
When you don't even know who's in the team?