I've come to the conclusion that I have a strong disposition towards feeling like I've actually done the hard work of deep comprehension, while also allowing my strong aversion towards doing the actual work to stop me from doing more than the bare minimum to sound knowledgeable.
In practice, the only method that I've found to counter that urge is to constantly self-analyze (i.e. ask myself the same questions that may come up in a deeper discussion) and interrogate my beliefs. By doing that, I force myself to confront the fact that I don't understand things as well as I believe I do.
Once I've broken past that mental barrier, it's far easier to actually commit to taking the time to fully comprehend a subject—the difficulty is primarily in identifying the barrier in the first place.