The satisfying feeling you get when you add a page to Wiki that no-one seems to have addressed yet, especially if several others add to it (favourably or otherwise), gives a sense of contribution. Even though most topics are all over the rest of the internet, and are common knowledge, the fact that you added it to Wiki first makes you feel like an inventor. 

(There are probably already pages like this - feel free to refactor. If not, this entry will provide a small sense of WikiSatisfaction).