It happens to Yeats in a London coffee shop. This is how he describes it:

My fiftieth year had come and gone,
I sat, a solitary man,
In a crowded London shop,
An open book and empty cup
On the marble table-top.
While on the shop and street I gazed
My body of a sudden blazed;
And twenty minutes more or less
It seemed, so great my happiness,
That I was blessed and could bless.

(“Vacillation, IV”)