The brunch you're enjoying is well because you're with lovely people, delicious food, and a hilarious conversation. Yet, you're feeling isolated, like you're emotionally a thousand miles from the rest of the world.  The thing about emotions is that they're not the same for everyone. Some people, for instance, have no problem having only a few friends or like spending a reasonable amount of time on their own.  Others, however, experience similar situations that can create an intense feeling of feeling lonely and unconnected. Understanding the reason you feel isolated even when you're in a group will make you feel more connected to the people around you and yourself.