It's one thing to act differently around someone because you're a decent person who wants them to feel at ease. It's quite different to approach the situation with the mindset of "I have to get these folks to accept me." In order to gain their favor, I'll transform into anything I believe they desire. That's not real friendship—it's imitation. Real friends will accept you for who you are without trying to change you. They know you better than you think (or maybe even know you well enough), which is why they can recognize your quirks and use them to your advantage. You'll never be able to fit all your friends into a category, but it's important to realize those categories exist so we can find ways to help our friends. So yes, it's normal to act differently around different people. The only thing that isn't normal is if you feel the need to alter your behavior in order to make everyone happy all the time. That's when you have problems that only you can fix.