I am a lurker by nature. I figure that someone has already said what I would say, why say it again?
To keep the site going.
To be honest, nearly everything has been said before. Fora wouldn't exist if everyone
thought that way. Yet, not everyone has been exposed to what is said. Nor has a
particular community had every conversation - and slight perturbations in a discussion
can have different effects on people.
Saying things that aren't all that original is what a forum is all about.