Oh, I have found out the proof that also great people can be naughty and to have the same flaws as common human beings.
Lord Byron did what a lot of silly tourists still do...he visited a historical place and he could not help carving his name on a wall to mark he had been there!
So this is the original graffiti, which, "Byron the hooligan" carved on a pillar in Chillon castle!
But he was Lord Byron, if he had been John Smith his signature would have been erased later to restore the pillar. In this case his signature was protected by a glass screen, maybe to let the posterity know that every artist can have banal weaknesses too.