Your mind is like a compiled program you've lost the source of. It works, but you don't know why.
The situation is far worse than that. At least a compiled program you can: add more memory or run it on a faster computer, disassemble the code and see at which step things go wrong, rewind if there's a problem, interface with programs you've written, etc. If compiled programs really were that bad, hackers would have already won (as security researchers wouldn't be able to take apart malware), drm would work, no emulators for undocumented devices would exist.
The state of the mind is many orders of magnitude worse.
Also, I'd quibble with "we don't know why". The word I'd use is how. We know why, perhaps not in detail (although we sort of know how, in even less detail.)
Another month, another rationality quotes thread. The rules are: