Martinizing is similar to refactoring in that it does not change the observable behavior of the code, but the goal is different. When I refactor, I am changing the design, usually in an effort to add a new feature in an open closed manner.
When I martinize, I am telling a story. The most important story being the desired behavior, but also a story of the hard earned knowledge acquired along the way. If I spend hours distilling some business concept. I want to leave a trail for the next guy to understand that a simple property assignment or conditional statement isn’t so simple. And of course the perfect way to punctuate that message is with a well written unit test.