The literal definition of the phrase that coined the "The exception proves the rule" says, in its literal legal interpretation, that just because there are exceptions to the rule, it does not mean the rule is not important, or effective.
As for the changing definitions, if the literal meaning changes, then so does the nature of the fact, discrediting its existence as fact.
I also don't understand why you have to make this personal? It's a running gag for you to call anyone who disagrees with your opinion a "troll", or some other sort of witty adejctive.
How am i a troll? I am defending my opinion and not insulting anyone in the process.
Unless you can prove without a shadow of a doubt that something is an universal truth, and no other argument about it has merits, it's not absolute.