I'm trying to find an old blues/R&B song, which I'm pretty sure was covered by the Grateful Dead, with the lyrics:

Crazy, Ain't It Crazy (repeat)
To Keep On Rubbin' That Same Old Thing

I've tried the DT, YouTube, Google, Bing, Grateful Dead lyrics, etc. ~ unbelievably, no luck. What could I be doing wrong?

I don't think this is something I dreamed up ~ I'm almost positive that such a song exists. Perhaps knowing the name of the original artist would help...

What I'd really like is a video link, second choice a sound file ~ something to email immediately to a certain party. Chords/tabs/lyrics to help me learn to perform it would also be great in the longer run.