That. Is the most simple reason that I compete with myself every day and no one else anymore. I've learned it keeps me more grounded and humble, I can love others more, I'm actually more successful and most of all I'm happier!!
Everybody isn't your friend. Just because they hang around you and laugh with you doesn't mean they're there for you. Just because they say they got your back, doesn't mean they won't stab you in it. People pretend well. Jealousy sometimes doesn't live far. So know your circle. At the end of the day, real situations expose fake people, so pay attention.
If you are a true friend, you are happy for that person and want them to be successful. If you have true friends and you gain great success in life, it's an inflated ego you may have versus what you blame others having issues with.