How should I keep track of the number of skills mastered?

Whenever I start a new course, I set a goal: by the time I have completed a course, at least half of the exercises in that course should be Mastered.

And it mostly worked, for the first part of my progress (ESPECIALLY when course mastery was based on mastery points).

Right now, the number of skills mastered is far above 400, which means that there's no more available Sun badges rewarded for achieving mastery.

How should I keep track of the number of skills mastered, and what will happen if I keep following pursuit with this goal and master thousands of skills?