[christoff12]

The key is to figure out what your learning process looks like.

For example, I discovered early on that I learn in three phases: 1. I get exposed to something (a concept, a process, etc); basically discover that something exists. 2. I then see how that thing is used whether through mentorship or tutorials or, increasingly, through trial and error. 3. I apply that thing to some novel problem.

Through this cycle of Discovery-Tutelage-Application, I can assess my level of comfort with new material and understand when my struggles are due to trying to short circuit the process.

It's likely that you have some form of learning process that is equally cyclical, yet undefined -- once you identify and codify those steps, you can evaluate your progress when it comes to acquiring new skills.