I saw Greta Gerwig's Barbie on the last Saturday of July. I went with some friends whose nine year-old girl went wearing a pink dress. I looked like the single uncle they invited out of pity. I liked the film, but I wasn’t gushing with praise when I came out. I gave it a six out of ten. Maybe a seven at a stretch. But what I did love was what it’ll do for Greta Gerwig and female film directors as a whole. It’s a certified billion dollar movie. The film has grossed $1.3 billion so far, and it’s still doing good business. The film that is now inextricably linked with it is Oppenheimer, the Christopher Nolan film about the creation of the atomic bomb. The publicity that the “Barbenheimer” pairing created was extraordinary. I don’t know whether the studios pedalled the idea from the outset or whether it was simply a fan-made viral sensation. Either way, it worked. Who could have predicted that t...