You can still have chemistry on screen without getting on with the person. But it just makes your job a lot easier if you don't have to gird your loins, if that's not quite the right phrase, every time you're going to do a scene with that person.
I love soup 'cause I don't like to cook. It's so easy to prepare, and it fills you up and gives you all the nutrients you need. It's a well-balanced meal, but you don't have to do a lot of preparation.
In an ideal world, it would not take a film star to get the media focused on mental illness.

