Is it normal to feel more alone in a crowded room than when you're by yourself?

You're surrounded by people, maybe even people who care about you, and yet there's a distance between you and all of them that no amount of small talk seems to close.

Loneliness in a crowd is one of the strangest feelings — invisible to everyone around you and impossible to explain without sounding ungrateful.

Have you ever felt completely alone in a room full of people — and did anyone ever notice, or did you get so good at hiding it that nobody could?