Sure!

Though here is more of a case of "once in a blue moon I got o the pizza place ... and I'm bored and tired of life ... and want to try something crazy for a change ... but then I see the same old stuff on the menu, I think man, this world sucks ... but now they have the Sushi-Harissa-Livarot pizza, I know next time I'm going to feel better!"

I agree it's a bit weird that I say that p(post|weekly thread) > p(post| monthly thread) when so far there are no instances of post|weekly thread.