Crowd. There was a time in my life when I felt so lonely being in a crowd. I think sometimes you feel your innermost sadness welling up when faced with a number of people who seems to have so much to talk about. Friends meeting friends. Lovers entwined in a romantic interlude. Family having a blast together.
I was alone then and for some reason got into the midst of a crowd going the same direction as I am. And there's nothing more daunting than being surrounded by strangers at a time when you want to be alone.
But they say sometimes, you can drown your sorrows in the happiness of others. Maybe it is true. I never did find out.