To come close to mastering a subject at undergraduate and graduate level takes a couple of years - it should be at the end of this two year period that formal assessments take place. I question the logic of formal assessments before them, other than to trap the unwary into taking modules that may or may not lead to something else, that will probably, for the first couple at least, deliver less than pleasing grades. If I took a couple of modules after the MAODE it would be to wipe-out the first two feeling dissatisfied with low 50s where a couple of mid 70s is where I peaked.
At some point as you study the 'fog will clear', like learning a language, the 'language' of your subject will come into focus. There might be a 'Eureka Moment', when the 'Penny Drops', some text, something someone says that changes everything and you cross a line forever.
For me this requires considerable reading and discussion around the subject - I have to make my own discoveries, to hear it from half a dozen voices first, ideally from different angles, until one voice, or collectively, they come into harmony.