Did you ever walk into a gathering — at a restaurant, maybe, or a party or a nightclub — where nobody there looked like you? Maybe their skin was a different hue. Maybe they were of the opposite gender. Perhaps they were much younger — or older.
Chances are, you became uncomfortable. You might even have left.
But if at least some faces in the crowd looked like yours, chances are you walked right in. And if they were participating in a mutual activity, you probably joined in.