What did john mayer do to taylor swift?

never heard that song! there is just one thing that i dont understand, why is she so famous ( nothing that im jealous) but come,on there is alots of artist who are better and why taylor always writes songs about boy who dumped her?? i mean she is a whore first she hooked up with joe than taylor, jake , cory chord oversheet and god know who else. i mean she got famous by kanye west dissing her at the vmas ( yeah thats the truth she know for her VMA's drama scene)