Always do a sanity check on every rule. Some rules were formed in moments of insanity.
(For instance, we often say "there is always an exception to a rule".

This statement ITSELF is a rule. Which leads to recursion.

We then say: "there is always an exception to "there is always an exception to a rule"".

This can be simplified to a more meaningful form as: "there is NOT always an exception to a rule" - a contradiction to the original rule.)

Oyeniyi Dada, From my musings.