I think that maybe for some like me, we try to post what little we can find or take ourselves, and other than that, I try to stay out of the way of what I call the "real" posters.
I make some comments when they are specific to the post or when I am flat out amazed at what you guys are able to find...but other times, if a post has replies and four stars, then I don't want to look like a zooperist and bump up threads with my opinion. This may sound stupid, but I think, "who gives a shit if I liked it or not? I hardly contribute".
If I knew that comments like mine are wanted then I'll start posting some select ones. I just don't want to clutter the forums and start looking like a freedom, grandad, or energy nuthugger.
