Sean Penn is just plainly talented

I was watching, nay I had to stop watching the film The Assassination of Richard Nixon last night because it was just too much for me. The first time I became aware that Sean Penn was a pretty talented actor was maybe Dead Man Walking, and certainly looking across the scope of his career from Fast Times at Ridgemont High (written by the then young Cameron Crowe) through Dead Man, 21 Grams, Mystic River, All the King's Men, etc., in all these movies he's pretty frickin' awesome. No question. One of my only memories of Saturday afternoon television is him beating the crap out of a couple of other prisoners with a pillowcase full of RC Cola. That is all I can remember from that film, whatever it was.
All of this is well and good, he's an actor par excellance, but his performance in The Assassination of Richard Nixon is something else entirely. He's both subtle and not subtle all at the same time. How do you do that? As the movie builds towards the assassination attempt and his life falls apart their was a growing feeling of helplessness from the depths, and when he finally fully breaks down after recieving divorce papers, I just had to stop. I couldn't go any further. I was seriously afraid that my life would be irrevocably broken if I continued watching this film. I was really effected massively by the beauty of this masterfully uncomfortable performance.
Now given the fact that I'm a big fan of existential films in general this is really saying something. I loved Fellini's La Strada, Ozu's Tokyo Twilight, and most recently the film Control. None of which did I have to stop watching. I made it all the way with all of them, although I had to take Tokyo Twilight in small doses over the course of a week.
So, am I recommending this film? Yes and No. If you're not hypersensitively emotional, then I'd say get into it. It's an amazing performance in a pretty well written and certainly well concieved film, but if like me you can be maybe a little too deeply effected by films or novels, then I would say think twice. It's unbelievably powerful stuff, although admittedly I have no idea how it ends.