Not only do you have to focus on the right information, but you have to sacrifice the great ideas to focus on the ones that matter. You fail to do this every day considering your desire to learn multiple languages and improve on numerous fronts. You think that if you make the task small and progress daily, the effort will not afflict you. This is partially true, as you have proven through your own experience, but combine all of these small tasks, and you begin to see that your ability to focus on one massive task has dwindled. Your ability to do in-depth work has disappeared in the shallowness of your numerous other endeavors.
Focus does not mean saying no to things you would never say yes to in the first place. It means saying no to what you ache to say yes to. That is making a sacrifice for the sake of the broader vision that is much more desirable, but requires far more focus.