"Act III, Scene iii" by Madeleine L'Engle

Someone has altered the script.
My lines have been changed.
The other actors are shifting roles.
They don't come on when they're expected to,
and they don't say the lines I've written
and I'm being upstaged.
I thought I was writing this play
with a rather nice role for myself,
small, but juicy
and some excellent lines.
But nobody gives me my cues
and the scenery has been replaced
and I don't recognize the new sets.
This isn't the script I was writing.
I don't understand this play at all.

To grow up
is to find
the small part you are playing
in this extraordinary drama
written by
somebody else.

From Lines Scribbled on an Envelope and Other Poems (FSG, 1969)