When you see somebody's good fortune, be happy for them, celebrate their good luck! As if they were your best friends and you wished them well. Find your own joy in other people's happiness. Even if they are strangers to you, be happy for them. Later on, once you learn how to be happy for others, it will be easier for you to learn your own happiness. Do not give away your power to anything or anybody else. You can decide whatever you want, and feel in any way you want. Enjoy, it can be a lot of fun!