Started learning programming. I set myself the goal of studying two hours per day and so far I have adhered to this plan. I follow The Odin Project, with Peter Hurford's suggested modifications.

Came up with a productivity system that has worked wonderfully since I adopted it three weeks ago.

Started tracking my time (using Toggl), which further boosted my productivity, by making me more mindful about how I spend my time and by providing me with information that I can analyze to draw useful lessons.

Together with a few other friends, experimented with a scheme involving reciprocal anonymous feedback. In light of the positive results, I plan to repeat the exercise and eventually write a comment or post about it.

Bought noise-cancelling headphones. I can now listen to audiobooks on airplanes, subways, and other noisy environments.