An interesting thing to note:
If one believes, as I do, that there is an exception to every rule, then this has two implications.
First, the notion that every rule has an exception means that if one believes something to be in fact a rule, then among other things one must provide, as proof, the exception to it. This is simple logic: if all mules are sired by horses, then to prove that something is a mule one (at least) must find the horse that sired it. Finding an exception to a rule does not prove that it is a rule (other things have exceptions too), but failing to find an exception means that it cannot, in fact, be a rule.
Second, if one believes that there is an exception to every rule, then this belief itself is being proposed as a rule. Therefore it must have an exception. Failing this, by its own standard, it cannot be held to be a rule. So does the rule "there is an exception to every rule" itself have an exception?
If so, then there must be at least one rule that has no exception.
There is. It is this:
There is an exception to every rule.