Hehe, that pressing of phone part was very relatable, it would be much better if you even had your earphones with you, it usually happens to Introverts.

As an Introvert I am always very comfortable with my inner cycle of friends,I can spend a lot of time talking with them, but when someone I don't know comes in, I get uncomfortable, my peace mechanism will be triggered hehe.
Trust me there is so much noise outside, we find solace in peace and quiet.
Many of the few that make it to the list of our friends should be very grateful.