[Sleeping position - head or feet]

Hi

I was told that we should sleep with our head on the opposite direction of our 'good' fengshui position as when we get up, that will make us face the 'good' position (ie our feet will be pointing at our good position instead). Eg if my good position is SW, then my head should be at NE when I sleep so my feet will be pointing SW thus i will face my good position when i get up... Is this true?
Thanks