This is really important to understand as there are many programmers who would not comment or not put proper comments in their own code. Also, they prefer to get puzzled by their own code but not letting others understand their code.
That’s a very subjective assertion. What if they can perfectly understand what they wrote, and could write it again given the same criteria? There is such as thing as overkill. Commenting is not a narrative. It’s hints. Code in many ways is self describing.