If you click on the finger with a string on it below any post, it puts that thread on your homepage to keep track of. If selected in your user settings, you may also recieve email notifications of any new posts to that thread.
Another way to follow any threads is to look at your user profile (click on your name on any post) and click on "show all users posts." There you will see all of your recent posts listed by Title, Forum, and Date.
We should all take ourselves seriously...and then crumple that image up and toss it out the window.