About being sad and selfish.

I am sad because of them.
They didn't do anything though, so why did I not like them being happy?
Because I think that they were being selfish.

Because sad people (like me) sometimes think that happy people are selfish.

Because sad people are tired.

They were tired of being selfless in the past, so they wish they were selfish.

I am sad.

I am tired.

I wish I were selfish.

I want to be selfish.

Ans as I wrote this, I think I am selfish.