Hi,
not all the people want others to be happy and healthy,not for all of them and not always.
You don’t need to believe that this happens to someone and he wishes the best for others.We are human and we all have faults,imperfections, we have interests. (all of us,but in a different way)
So, yes you can learn how and when you want to give best wishes to others. It’s when you love yourself.
Let me explain. When you love yourself,you love others,and when you love others and you care about them,you have compassion.
You don’t want others to be in pain. It’s simple and true. As you want the good for yourself and you wish to be happy and healthy and be okay,so you want it for others,too. You don’t need to wish the best for all the people you meet, the meaning hides behind this: don’t let other’s imperfections (disaffection,disappointment,evil,etc) ruin your world or effect your life.