That was astonishingly difficult to parse. It's a good sentiment, though.
I also found it hard. For the benefit of the next person, here is a rewritten version:
If you don't know how to unknow things, then you also don't know how to know things.
Or, passing to the contrapositive,
If you know how to know things, then you also know how to unknow things.
Or,
One who knows how to know things must also know how to unknow things.
Rules: