On Activity page there is a Tag Cloud that shows the overall tags on MAS
The Tag Cloud (you enabled it I see) here on your profile, shows YOUR tags. That means the tags that you have added to your content on MAS. So here you can see what subjects occupy you the most, and click the tags to find that content.
I was curious to see which topics you were mostly interested in, so I looked in your Tag Cloud (you can turn it on in widgets). TF2 of course reins high, but, not at the top ! ....I think you should get with the program already !