Most maps fairly accurately measure the coastline of a place. Their granularity of topographical measurement is good enough.
In other words, it's not if you understand a concept but how deeply. Also, it's hard to sit down and list all the complexities of concepts. You could be understanding a lot more complexity than you realize.
https://en.wikipedia.org/wiki/Coastline_paradox
Most maps fairly accurately measure the coastline of a place. Their granularity of topographical measurement is good enough.
In other words, it's not if you understand a concept but how deeply. Also, it's hard to sit down and list all the complexities of concepts. You could be understanding a lot more complexity than you realize.