The fall off of Katy Perry should be studied for decades, possibly even generations.
She went from having the most popular songs being heard on the radio every 15 seconds, to being practically non-existent in the music scene.
You want to know what is practically existent?
People that say things they wish they didn't say, people that do things they wish they didn't.
At the end of the day the cards you are dealt are the cards you have and you need to learn to live with them.
No matter who dealt them, or who gave them to you, regardless of how close they are to you, whether a girlfriend or a leader of a foreign country, they are what you have.
We are all people and we all make mistakes, we all have opinions and thoughts on others. Those thoughts change overtime and cause people to feel distant to those they once felt close to.