True happiness resides within you. Most people are searching for happiness outside of themselves. That’s a fundamental mistake. Happiness is something that you are, and it comes from the way that you think.
If someone comes into your life and has a positive impact on you, be thankful that your paths crossed. And even if they can’t stay for some reason, be thankful that somehow they brought joy into your life, even if it was just for a short while.
Life is change. People come and go, some stay, some don’t and that’s okay. Remember the good times and smile that it happened.