... is usually nothing more than a huge bubbling well of self-pity, cynicism and lack of self-confidence.

No one has to be alone.
Especially in this the era of the internet, where people talk without ever meeting, without having to live with the reputation that they may have in real life. The lonely seem to be drawn to the internet, but so are those that know how to listen.

No one has to be useless.
Being useless only happens when you let yourself be useless. There is always something that you can do to help others, or even to Help Yourself! If nothing else you are already being useful by adding to the great wonder that is E2.

The hollow feeling is nothing more than loneliness, loneliness because no one came to see you, or called you, or sent you an email. It is just loneliness, which is perhaps the most commonly and widespread emotion.

All these lonely people, all of them have one time or another questioned their own worth, the value of their lives or the impact that they are making on the world.

I have seen popular people pine after one person in particular, drink themselves stupid trying to make the pain go away when the person seems to ignore them. What is it that drives them to this? It is the feeling that they are not important, that no one cares, or that she/he doesn't care.
At the same time I have seen the object of their affection cast worried glances at them, seen them go to the lonely person's friends and ask if they know what is wrong. They genuinely care, they worry and seeing a pain they try to help.
But wrapped up in their cloak of loneliness and self-pity, the lonely miss the signs that people care.

And thus they stay miserable and alone, they push people away by assuming that no one will come to them anyway...