In my experience, if you can’t explain a thing, it’s usually because you don’t understand it; that ability to explain is practically what it is to understand a thing (with notable exceptions for eg. language difficulties, or for simple hand-eye tasks, which this shrugging abdication(abnegation?) of explanation does not even pretend to try to meet).
(shrug) Sorry, I can’t explain this. Some things are so obvious that they are very hard to formally explain.
In my experience, if you can’t explain a thing, it’s usually because you don’t understand it; that ability to explain is practically what it is to understand a thing (with notable exceptions for eg. language difficulties, or for simple hand-eye tasks, which this shrugging abdication(abnegation?) of explanation does not even pretend to try to meet).