Something that sticks out to me from Charles Dickens' A Christmas Carol is that the ghost of Jacob Marley was ordinarily forbidden to interact with the world. Because he didn't care for others when he was alive, he was condemned to roam the earth for all eternity as a mere observer. He could watch what people were doing, but he could not participate or influence them to do good. They could neither see nor hear him.
What went through my mind when I read that was that I often feel this way. Since I have a hard time jumping into conversations, I mostly take the role of an observer. But my situation is different from that of Jacob Marley, since there's always a possibility that, at some point in time, I can positively impact someone else. Maybe someone will appreciate what I write, or I'll finally be able to get a comment into a conversation that makes people think.
Of course, there's always the chance that a lot of people won't listen to me. But there's also a chance that they will. That reminds me of another scene from A Christmas Carol. Scrooge's nephew, Fred, is talking about Scrooge at his Christmas party, and he says that he'll continue every year to invite Scrooge to his Christmas gathering, since the party could bring Scrooge some pleasure. Granted, he thinks Scrooge will turn him down each time, but he at least wants the invitation to be out there for him each and every year. And Fred says that his visits to Scrooge may influence his uncle to be a little nicer to his employee, Bob Cratchit.
Scrooge looks like a lost cause, but Fred acknowledges there's at least a possibility that he could plant a seed in the hardest of hearts. Unlike Marley, Fred is able to interact with the world--to get others to notice and pay attention to him in some way. As a result, he can be a force for good.