Ryan Coogler’s Fruitvale Station—and now Greta Gerwig and Lady Bird. Greta has a kind of momentum that feels like it must help contain a million good ideas from flying out of the atmosphere.

“There’s no time for despair. Despair is a privilege.” Since beginning her campaigning in 2018, Greta has met many world leaders and said she has been “shocked to see how ignorant” some ...