> Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

The expression "by definition" is misplaced here. The first proposition "Debugging is twice as hard as writing the code in the first place" is not a definition. At best, we can treat it as an axiom. In any case, the conclusion "if you write the code as cleverly as possible, you are not smart enough to debug it" does not follow by definition.