I would never have heard of "The Humbling" if Google news alerts didn't pop it up for a Shakespeare reference. It stars Al Pacino and is based on the Philip Roth novel, which I have not read.
The play opens with Pacino, dressed in a trenchcoat and looking like something out of Death of a Salesman, practicing the ages of man speech from As You Like It. It looks at first like he's trying to remember his lines, but we soon see that he is trying to decide how he's supposed to deliver them. The line between his acting and his reality is becoming a blur, and he's having trouble differentiating between what he feels and what he's only pretending to feel. After an event at the performance sends him to the hospital there's a funny scene where he's moaning in pain and asks the nurse, "Do you believe that? That I'm in pain?" When she says she does he says, "I could do that better. Let me try it again," and tries a different delivery. It's not that he's faking. He just can't escape analyzing his own performance, even when it is reality.
Now we get to what I like to call the "not Shakespeare" part of the movie. He goes to rehab and meets a crazy stalker lady who wants him to kill her husband because as an actor he's got experience. Then he comes home and starts a relationship with the daughter of some old friends of his, who happens to be a lesbian. He's then quickly introduced to the past loves of her life, including the department head who she slept with to get her job, and a post-op transgender man who still wants her.
Or maybe not. Scenes often play out, only to reset as if they'd never happened. It becomes obvious that Pacino's character is losing his mind, and some if not all of the above may not have ever happened. Throughout the film he engages in regular videoconference updates with his therapist, who also has trouble distinguishing what's actually happening from what Pacino thinks is happening.
Now, back to the Shakespeare. After vowing never to get on stage again, Pacino is ultimately pulled back for a performance of King Lear. I mean sure, why not, a guy has a nervous breakdown during As You Like It, goes to rehab, swears off acting, of course you want to just throw him right into Shakespeare's Mount Everest. I'm ok with that, though, because it means we get to watch Al Pacino perform some of King Lear.
It's an interesting movie, but it's not a Shakespeare movie. It's mostly Pacino, but in a way that I would have liked even more Pacino, if that makes sense? He's surrounded by this crazy cast of characters that are all trying to take the focus away from his character and I found them more of an annoyance than anything else. It might be interesting if you've read the book, I suppose. Or if you're a "see everything" Al Pacino fan. But other than that it didn't do much for me.