Oh, dear. Um, sorry to burst your amour propre, but Terry Pratchett beat you to the idea, if not the exact quote:
The Last Hero:
Six Beneficient Winds: But … they’re so old!
Mr Saveloy: Indeed, and of course, this is true. They are very old barbarian heroes.
Six Beneficient Winds: Oh, my …
Mr Saveloy: That’s right. They’ve had a lifetime’s experience of not dying. They’ve become very good at it." …