Absolutely. In life, most people are "normal", almost by the definition of normal, but there's a big penumbra of people who don't habitually and reflexively conform to normal. If you're a little bit odd, you spend effort suppressing it and actively conforming. In autistic circles, this is called "masking" for behaviors deemed autistic; in LGBT circles, this is called "passing", and so on. But once someone has fallen sufficiently far from the middle of the normal distribution that they can't pass, or can't be bothered to pass (it can be a lot of work), they stop trying to pass and you can spot all their non-normal behaviors.
(What is "normal" is of course culturally determined and varies by your local culture, social class, etc, and covers all sorts of things. Americans and Brits are told to hold forks differently, for example)