Mikk had over 150 days /played in WoW as of may 2006. Even though he couldn't play for the first couple of months after the EU beta.
Instead of just finishing a mod he had started coding, Mikk got annoyed that he couldn't code on wednesday mornings, and wrote the first version of WoWBench. Which he then came to WoWWiki to document.
Instead of doing what he came to WoWWiki to do, Mikk got annoyed with the help pages and generally everything under "WoWWiki:", and took several weeks of twiddling with that instead of just getting his job done. This necessitated a long break from actually playing WoW. (See point 1 though)
Mikk took it upon himself to categorize every single template in the "Template:" namespace into Category:Templates and its subcategories.
Mikk dinged 2500club membership after only ~2 weeks of actively contributing. (Mostly due to point 4 though)