Are multiplex cinemas really completely filled so often? We always just show up 15 minutes before the film starts and never had any trouble. I mean, we are sad

Are multiplex cinemas really completely filled so often? We always just show up 15 minutes before the film starts and never had any trouble. I mean, we are sad when we can’t find a row with no one directly in front of or behind us … Obviously you shouldn’t watch the new Avengers movie during the first couple of weeks, but I wouldn’t watch it during those weeks even if I had no flat rate. Cinemas full of people are awful. (Also, I think I can even order online, but in practice that was never necessary and I do want to sit next to my friends.)