In regards to this, what approaches can people take to become more T-shaped? I consider Hacker News a very good resource for learning, however, I sometimes feel overwhelmed by the amount of information I miss out on.
Something that I like to do is try to come up with every topic that I can possibly think of. I just thought about what I might interact with on an average day and came up with clothing design, restaurants management, window installation, gasoline manufacture, and book binding. And then I try to find out the bare basics about each topic, no matter how weird or esoteric.