Taylor Swift is a singer-songwriter, businesswoman, best friend to the stars and bona fide expert on breakups. That's why when she says, "Karma is the breeze in my hair on the weekend," it's both witty and a little bit mystical.
I'd grade her on that understanding if I were a professor, but there's no way she's going to get 100% right. She may have an inkling of what Buddhism means, but that's all.
Her song, "Clean," focuses on the end of a relationship, but that's not the only thing it has to do with. In the lyrics, she also mentions drugs and alcohol.
The meaning of "Clean" is to let go of anything that can be self destructive for you. This includes things like relationships, drugs, alcohol, and cutting.
It's about letting them go for good and not risking them coming back. In the lyrics, she says, "I'm clean" and it means that she is free of them and has moved on.
She wrote it after her Red Tour in London and realized that she wasn't interested in Harry anymore. She had gotten used to him calling her and texting her but now she wasn't in need of them anymore.
She reacted to this by writing the song. It's a very powerful song that has helped people with their problems. You can't help but feel better after listening to it, and if you are dealing with something similar, this could be the song that helps you move on.