What do you think?
I think there is no criterion for importance. The people whom we consider important do not consider themselves important. Only others perceive them to be important. If importance is a matter of perception, you have to first perceive yourself important.
You know what? by not doing anything, you're actually contributing. I mean if you don't do anything that's against the law and you abide by it. By being a good citizen you're already doing good for your society.
Plus if you're a working man and pays his taxes, you're helping the government with it.