This was my mantra, and it was an important part of my path. I grew up believing that my role was to make people happy, and my value was tied to whether I was successful at that. So Buddhism was a revelation in that it proposed that I have my own intrinsic value and that everyone is responsible for their own happiness. I can't make you happy -- you have to make that choice. I can try to act ethically, with kindness and compassion, but I can't control whether that makes you happy.
So why metta, why wish for another's happiness, safety, health, and ease?
It's about training your mind, opening up to the common experience of sentient beings, loosening your grip on the solid people you project the wishes onto, letting go of your own definitions of what that means.
Metta is about letting go.
May you be happy -- however that manifests for you. You don't have to meet my definition of happiness. YOU DON'T HAVE TO SMILE. I wish that you have happiness that's not tied to a new iPhone or a text from your crush, that you find a deeper source of contentment that lasts, that you see that happiness is not tied to external circumstances. May you find that, in your time and your way, which may not be mine.
May you be safe -- I have adult children; I learned a long time ago that I can't control whether someone else is safe. With kids, ultimately, all you can do is hope that you've passed on enough information so that they avoid those dangers that are avoidable. Then trust. May you avoid the risks you can and not be so frightened of the ones you can't that you get paralyzed.
May you be healthy -- and may you have ease with whatever level of health you have. (See safety.)
May you live with ease -- I hope that you can find a way to accept what you cannot change and to change the things that you can. And the courageous wisdom to figure out which is which.
I can't make you happy or keep you safe or give you health or put you at ease. But I hope that you find it. May I create the conditions that will enable you to uncover that in yourself.