@Shapeless,
Think of it as a big family tree or organization chart. You can click on a topic tag and explore that branch of the family tree as much or little as you want by clicking the my topics, my posts, my tags links at the top of the page. They customize to the tagged topic category you happen to be in. To get back to the top of the tree to see what other branches are there to explore, click on the abletoknow logo in the upper left corner of the page or on the able2know link right below it that shows you the relationship of the branches and twigs you are currently on. Click on those links again at the top of the page to get a completely different set of my topics, my posts, my tags within the next branch of the tree you explore by clicking on another one of the category tags.