The poem opens with a sly question: which of the people who refuse to follow the crowd actually expect their moment of recognition? There's a quiet joke in it. Nonconformists are supposed to stand apart, yet the speaker suggests they still hope, somewhere, to be vindicated.
Then the poem turns inward. The speaker's words "keep differing" with their lips, so the mouth and the message don't match. The title, "I beg to differ," is a polite phrase for disagreeing, and here the disagreement happens inside one person. It could mean the speaker says something other than what they intend, or that what they write or think can't be spoken aloud without changing.
The mood is dry, wry, and a little self-mocking. The speaker doesn't seem angry. They seem amused and slightly uneasy at being a dissenter who can't even agree with themselves. The short lines and the lack of fuss make the humor land softly.