This always amuses me, because I'm very quiet and introvert until I get to know people, and people who don't know me sometimes assume this means I'll be anxious in crowds.
But in fact, while I don't particularly like crowds, I learned very young that if you don't particularly want to interact with people, crowds are great. I can sit down in the middle of a party and spent 3 hours just observing people mindfully and be content, and most of the time people will ignore it.
But you can also act totally outrageous in a crowd, and people will tend to try to ignore you, not pay attention to you until/unless what you do personally affects them.
A useful exercise in that respect is to go a day and try to keep a mental count of how often you notice yourself thinking about your own actions vs. how often you notice yourself paying attention to someone elses action, and then at the end of it, try to recall those other peoples actions. Not only will most people find they spend far more time worrying about their own appearance or actions, but that they will have forgotten most of the interactions the noticed with other people even when trying to keep mental tabs of them.
Most things that most people do simply isn't that interesting to other people. Heck, most things that most people do isn't that interesting to themselves other than in the moment.