The motif of theatre is interesting: poetry and acting are both performative media, though the former is often treated as thinly veiled autobiography and the other as authorial ventriloquism. In this poem, by "drawing back" the curtain to "show the parts we've played", Sheers is effectively breaking the fourth wall in a theatre by emphasising the conscious construction of the art form through which he's expressing himself. This is ironic as he's exposing himself through a carefully created poetic voice.