Everybody has the power to make someone else happy.
Some do it by entering the room, while some do it by leaving.
Happiness comes from within, when your happiness depend on someone first it pushes away other person and second you will not be happy, because other person is not responsible for your happiness.
You can't control everything. Sometimes you just need to relax and have faith that things will work out. Let go a little and just let life happen.
Letting go of people out of your life doesn't mean you hate them, it simply means you respect yourself. Not everyone you meet is meant to stay.