If you dive headfirst into the ocean of learning, like a blind tadpole swimming around, you may get caught in a meaningless whirlpool. Because if you only learn without verifying your learning outcomes, without practicing, and without producing some useful projects, then this learning is useless; it is merely input without output.
On one hand, you need to avoid getting lost in the flood of information and select high-quality information for input. This process is like filtering out appropriately sized iron ore from a pile of sand, discarding all the useless fine sand (information selection).
On the other hand, the remaining iron ore needs to be carefully examined to remove impurities. The purified iron ore should be smelted with my original metal pieces to forge a larger and more complete metal piece (organizing, summarizing, and outputting knowledge).