I think this is a total play-off of the old saying "The grass is greener on the other side."
I know the song refers to a woman, but I think he's kind of singing it about life in general. He's saying "Hey, I don't need to go anywhere (like the other side of the fence where the grass is greener in a metaphorical sense) or change anything to know what I got is good." He likes exactly where he is and he doesn't need anything better, even if there is better out there, because he loves where he is and he's perfectly content.
I think this is a total play-off of the old saying "The grass is greener on the other side." I know the song refers to a woman, but I think he's kind of singing it about life in general. He's saying "Hey, I don't need to go anywhere (like the other side of the fence where the grass is greener in a metaphorical sense) or change anything to know what I got is good." He likes exactly where he is and he doesn't need anything better, even if there is better out there, because he loves where he is and he's perfectly content.