The speaker opens by calling himself ordinary, then drops a strange claim: ingenuity is better than thinking. It sounds like someone who has learned to get by through clever improvisation rather than deep reflection, and who is a little suspicious of his own mind.
The puppet-plays image carries most of the poem's feeling. The speaker acts in them, and they keep handing him new roles, which suggests a life of performing rather than choosing. The odd phrases "a late foot" and "a head full of order" make him seem slightly out of step, always arriving behind the beat, yet mentally tidy and controlled.
The last stanza is the saddest. He sees that joy is missing and calls it art, as if the emptiness has become something to admire from a distance. Then he admits he works to leave no room for joy at all. The mood is dry, wary and quietly self-aware, with a faint ache underneath the detachment.