There are times when I hear a cover of a song and it helps me understand the original song. Not so odd. What is odd is when I don't like the original until I have the time to get the interpretation through the cover. Odd when a cover is training wheels for the actual song.
Example: I have a fondness for Jeff Buckley's version of 「Hallelujah」, and only after listening enough to it did I really begin to appreciate the Leonard Cohen (original) version.