At first, you'll be uncomfortable with Pat's unusual behavior, but it will immediately feel much better once Tiffany enters the scene. Even though his behavior doesn't change, once there's someone else like him, you feel immediately better. Why? Because it normalizes him. When we meet somebody like us, we immediately feel better, more acceptable, less worried what others think of us. We feel the same about others.
In this film, all the scenes, dialogs, and emotions are real and solid. The acting is superb and the story surprising on many occasions. This is definitively the best performance Bradley Cooper has given, and Jennifer Lawrence is his match on every level, we just don't spend as much time with her as with him. Robert De Niro plays a great character, and Chris Tucker fits right in. Everything is perfect.
This script even plays the "lie" right, and the final moment got me yearning for a girl to cuddle and love. It has been a while since a movie made me feel that. I just can't find anything wrong with it. If you want to pick something negative, I'd say that the professional dancers are not good actors. That's it.
The only reason not to watch it might be because you don't like that kind of story. It's about average people, with average surrounding, salary, homes, and lives. There's nothing marvelous, scintillating, or stupendous, just normal.