Ask HN: How should I measure a goal to “Master JavaScript”?

I've been using JavaScript in various personal and client projects for a few years. My understanding and confidence with it has been consistently increasing, but I have never made a truly focused effort to thoroughly learn it and how best to use it.

Recently I've set a personal goal to "Master JavaScript", I feel I've got a decent collection of study and reference materials (books, docs, lists of recommended resources) to draw on, as well as some projects in-mind for applying my learning. However, I would really like to set some measurable means to judge my progress and success by. A few ideas for doing this are:

- Successfully complete the interview process for 3/5 JavaScript engineer positions I apply to.

- Have X number of Pull Requests to large Open Source projects accepted.

- Build an application that includes X, Y, and Z.

As you can see, I'd like these goals to add a specificity and measurability on top of the general goal of "JavaScript mastery". Any improvements upon those above, or novel suggestions are greatly appreciated.

Thank you.