AS SOON AS I GOT BACK to New York from my Covid-period cave, I marched up to the Museum of Modern Art to see “Cézanne Drawing,” organized by Jodi Hauptman and Samantha Friedman, because, I mean, if you’re a painter, you’re supposed to somehow know how and why Cézanne was a genius. But what’s a genius anymore, and what does that even mean? Here was this introverted guy who lived in a vacuum, who ruffled up the picture plane like he was running his hands through its hair, unpinning it. I had seen an amazing portrait show a few years ago in Paris, and I knew that the likes of Elizabeth Murray and