Just how hard is it to be happy? In the effervescent new comedy from writer/director Mike Leigh ("Vera Drake," "Secrets & Lies"), Sally Hawkins stars as Poppy, an irrepressibly free-spirited school teacher who brings an infectious laugh and an unsinkable sense of optimism to every situation she encounters, offering us a touching, truthful and deeply life-affirming exploration of one of the most mysterious and often the most elusive of all human qualities: happiness.