Choose Depth Before Adding Another Topic

The temptation to start something new is almost always stronger than the discipline to finish what you started. A new subject feels exciting; the current one has gotten to the hard part. But shallow knowledge of ten things is far less useful than solid knowledge of two. You can't build anything real on a foundation of half-understood ideas.

Go deep enough in one subject to actually use it — to solve a real problem, build something, or explain it clearly to someone else. That's the threshold where learning becomes capability. Only then does it make sense to broaden. Depth first, breadth second.