This review may contain spoilers. I can handle the truth.
Mao Zedong once said "never forget class struggle!" and this movie makes a similar point. This movie is the story of the non-magical Jacob Kowalski as he learns the Dumbledore's secret rule for happiness. Kowalski, whose memory of his witch gf was erased by the wicked Grindelwald, is reminded of Dumbledore's own maxim (lightly paraphrased), "Never forget gash, muggle."