Keeping up with the world of software engineering can seem daunting, especially when you have an explosion of technologies in diverging areas. And with all that, yesterday's experience can appear useless today. If you seem to be drowning in knowledge but gasping for insights, then this nugget of wisdom can help.
Understanding pertains to concepts. Rather than data, it's the way you think about data. Understanding is not about Python, Kubernetes, or Raspberry Pi. It's the way of thinking that leads you to understand all these subjects, should you so choose.
Efficiency, on the other hand, is like warming your "information cache" so that you can achieve goals quickly. Yes, you could learn Kubernetes if you want, but if you don't already know it, your lead time might be long. Also, like any cache, it goes stale very rapidly.
When you seem to drown in knowledge, remember that there are very few important concepts that you really need to understand. And these you must understand fully. But other pieces of knowledge are merely volatile data that needs to be interpreted just-in-time. The new frameworks, tools, utilities, are part of that volatile date. But the principles they're based on are the timeless concepts.
Thus, you don't necessarily increase understanding by randomly consuming knowledge. Be okay with not knowing things, since you can "know" them when the time comes. That way, you won't drown in information.