I was reading the Wikipedia article on the phrase Perfect is the Enemy of Good today, and interestingly enough I had always misinterpreted the meaning. What I thought was meant to dissuade someone from a kind of psychological perfectionism, had a bit of a deeper, mathematical meaning:

The Pareto principle or 80–20 rule explains this numerically. For example, it commonly takes 20% of the full time to complete 80% of a task while to complete the last 20% of a task takes 80% of the effort. Achieving absolute perfection may be impossible and so, as increasing effort results in diminishing returns, further activity becomes increasingly inefficient.
Interesting.

Thoughts? Also what else does the Pareto principle apply to?