It seemed peculiarly sad to sit here, thirteen hundred years before I was born, and listen again to poor, flat, worm-eaten jokes that had given me the dry gripes when I was a boy thirteen hundred years afterwards.

It about convinced me that there isn't any such thing as a new joke possible.

Everybody laughed at these antiquities -- but then they always do; I had noticed that, centuries later.
However, of course the scoffer didn't laugh--I mean the boy.

No, he scoffed; there wasn't anything he wouldn't scoff at.

He said the most of Sir Dinadan's jokes were rotten and the rest were petrified.