Yeah, that is one of the only true things they say. It does make it feel like you'll never be happy again.
Like, when I don't smoke for a while, I'll be like, "::sigh:: What should I do? I want to smoke. Let's sit here and do nothing. I'm depressed." Yada yada yada

It happens to me. I just keep busy, and in about 2 days or so, I'm back to being as chipper as ever.