He always seemed to have an extremely accurate but pessimistic view on life, and he's one of several 'ironic knights' in the show (With Brienne (female but is the most honorable knight in the kingdom) Jaime(brought shame to himself by making the noble action)). But yeah, I don't remember him dropping one liners like that in the book.
The more I think about it, the more I think this show could suffer the same way the books did when many of the remaining best characters die or go through shit. Right now it seems like the show is being carried by Cersei, Margery, Tyrion, Tywin, the Hound, Jon Snow, Daenarys, Bran, Petyr, Olenna, Oberyn and Arya. Tywin, Oberyn and the Hound are dead men walking, Olenna is out of the picture, Tyrion and Daenarys' stories are about to go into complete shit. I don't know how much people care about Bran already (I think Hodor is the only character people care about in that group. Maybe summer). I think it's up to Ciar?n Hinds to make Jon Snow's arc not boring. Arya's storyline is super strong and honestly carried the last couple books. I think people are tired of Cersei and I'm bearish on how her craziness will go, but her march of shame should be good.