If you don't know what "dumber than a sack of hammers happy" means now, watch Miss Teen USA 2007 - South Carolina answers a question and then come back to me. I'll wait.
To be fair, I'm sure she was flustered, but really, come on, can't people string a sentence together? One that, like, has an ending that has something to do with the beginning that has something to do with the question asked, like, okay?
The sad thing is, I'm sure she'll do ok in the world, for some reason society these days seems to reward the bim-tards.
Isn't that "dumber than a sack of happy"? :)