This is a much more tenuous link than the first part, but bear with me: the souls affected by Big Mom are basically ghosts.
No, really. They're spirits that have been removed from their original bodies. Think about it.
But you know what? You make the most of what you have. That's a good life lesson. To quote Monty Python, always look on the bright side of life.
Try doing that. I know I've been far from a positive person at times, but I want you to go to someone who matters to you and tell them you appreciate them. It's a quick thing to do, and maybe it'll make their life just that bit brighter.