Hi BBB! I've been lurking on A2K for a while, and I think you're one of the nicest posters here.
I think the problem is that no one has explained how to tag topics starting from the first step. (If someone has, then I apologize for repeating this!)
First, click on a thread that interests you. (Be aware that you actually have to be in the thread in order to tag it.)
Then scroll down to the very bottom of the page. You'll see a little box that says, "My Tag Words." It has a white bar in it. The white bar is where you enter your tag words. Most people use two words, separated by a comma.
For instance, you could tag the thread, "Afghanistan, news." Right under the white bar, you will see a green button that says, "Tag Topic." After you enter your tag words, press the green Tag Topic button.
You have now tagged the topic. If you want to find it again, just go to the top of your screen. You'll see a tab that says, "My tags." Click on that, and you will then see a list of your tagged topics. Then you just click on the thread that you want.
I hope that helps you. (Btw, I'm sorry to hear about your dog. But I'm glad you have the cute new puppy!)
(goes back to lurking)