Lyric discussion by miasnape 

Cover art for Come on Home lyrics by Franz Ferdinand

I think it's about leaving the person you love so you can both fufill your dreams, but keeping your love alive so that when it's possible you can be together again. The last lines:

"So come on home But don't forget to leave"

seem -to me- to indicate that it's really important to the narrator that his lover does what they need to do, and recognises that before they can be together again they need to be apart.