I have found that it's best to focus on specific tools, and become good with them, but always be ready to change. ADHD-style "buzzword Bingo," means that you can impress a lot of folks at tech conferences, but may have difficulty reliably shipping.
I have found that I can learn new languages and "paradigms," fairly quickly, but becoming really good at it, takes years.
That said, it's a fast-changing world, and we need to make sure that we keep up. Clutching onto old tech, like My Precioussss, is not likely to end well.