It’s likely that at some point we will also be able to represent a scan of the human brain digitally as code and data. Assuming we don’t separately make a huge number of leaps in neuroscience which are far from assured, it will be very likely that we can get the appearance of an operational human brain simulated digitally well before we gain much if any understanding of why it does what it does.

All that is to say, being able to build something is not not not the same thing as understanding it.