Here is a strategy that has worked well for me. 

Take a result you want to understand and try to prove it on your own. 

If you succeed, great! If not,  peek at the beginning of the proof and close the proof the moment you reach an insight you weren't able to think up on your own. Try to prove this insight, and try to complete the proof with this insight at hand. 

If you succeed, great! If not, repeat. 

In my experience, trying and failing to prove a result gives you a good appreciation of the proofs that do work. Constructions which might otherwise seem artificial often make sense as overcoming some barrier or other that you stumbled upon. 

Making sure that you have comprehended a concept
Is a simple LM317-based laser diode driver safe for powering a laser diode?
https://www.youtube.com/watch?v=iuMngik0GR8 (the diagram is at 1:37)


I've been told the the proprietary drivers offer some extra protection from very short spikes (on power up and shutdown) in the current which laser diodes are very sensitive to and might be damaged from. But isn't the LM317 regulator taking care of that itself already?

I've been told this from people who actually sell commercial laser diodes so I'm thinking they might be showing some bias.
