Not sure, but to me this sounds a lot like the song from Paint your Wagon. (I was thinking that it came from The Way the West was Won, which would be more ironic.)
Where am I goin'? I don't know! Where am I headin'? I ain't certain! All I know is I am on my way.
When will I be there? I don't know. When will I get there? I ain't certain. All that I know is I am on my way.