Why am I so shy around big crowds, but when I'm with one friend than I'm fine?

Sometimes the thought of everyone's attention turning on you can create an overwhelming feeling and cause you to get anxious. I have this issue too!

Sometimes it can be intimiditatong or even overwhelming to be in the presence of more than one to a few people. People are unpredictable, and the more you have the more potential for unpredictability there could be.

Maybe you will be comfortable with that one friend you are with. You may be going through social anxiety which is when you feel uncomfortable around a lot of people

You may be shy around big crowds but when you're with friends you don't face much challenges socially because around big crowds you might not be familiar with what is going on or the setting you're in to feel comfortable to open up, and this is why you end up hide away from a larger group of people,whereas compared to when you are with friends, it's a more familiar setting because you may have meet them before somewhere and gained trust in them which leads it to become more comfortable and supportive for you to not be so shy to speak up.

Being shy in big crowds while still feeling fine with your friend is okay. It may be because your friend is someone who you trust and you're not afraid to be authentic/expressive around her.

You may have social anxiety. Since you know the one friend well, you're fine with them. But lots of people, then the anxiety sets in.

Sometimes we feel comfortable with the person we are used to but it is hard when we meet others as we tend to worry how they may judge us

This sounds exactly like me. big crowds make me want to shrivel up into a ball. But with my friends I’m perfectly fine singing and dancing. I think it’s social anxiety. Which means that in big crowds or with people you’re not familiar with you start to panic almost. You freeze up and can’t think of anything to say.

You're shy because you don't know who is in the crowd, you fear that they may judge you. You're fine with your friend because you know they like you and already accept you for who you are.

Some people prefer small crowds and some other people prefer big crowds. Everyone is different, there's nothing wrong with that.