When Ward Cunningham was on our team, I learned a lot about building Wikis. He walked me through my first Wiki page. He probably didn't expect that 4 days later, I'd have more than 500 Wiki pages (he added a counter to my wiki!)
Ward told me Wiki Wiki was Hawaiin for fast, and he wanted to simplify publishing (the writeable web). This explained away my initial complaints of formatting and features, and I adopted the mindset of shapable content you can evolve over time. I thought of Wikis as notepad for the Web.
Ward and I had a lot of insightful conversations around various Wiki issues: one Wiki vs. many, choosing namespaces, choosing names, collaboration ... etc. The most important lesson for me was to think in terms of great pages. This meant, choosing better page names and make pages that matter. How to eat an elephant? ... one bite at a time. How to build a useful Wiki? ... one page at a time.