Of course, it's perfectly fine to go to a movie by yourself. I mean, I'm an only child, so I've been seeing movies by myself since probably 1990. Even now, with me being a film critic, there's a lot of stuff that I go through by myself just given the time of day that it is. So yeah, there's nothing wrong with seeing a movie by yourself. To truly know yourself, you gotta know how to be by yourself.