This track from Taylor's fourth studio album RED tells the story of a celebrity who had it all- a glamorous life and all the tabloids and lights to boot. However, after her secrets were leaked all over the world she decided to move away from Hollywood and disappear from the spotlight forever.
The song is about how a star will show up and transform themselves for the limelight and then doubt herself when people tell them they are "lucky". It's also about how the fame and fortune you're getting doesn't always make you happy or even safe.
It's a very common theme in music that you don't need to be famous or rich to be happy, and this is something that Taylor understands and tries to convey in her songs. She says that while she may be scared of some things in the past, she knows that being able to sing and get on a big stage is worth it, but she will eventually leave it all behind for a more simple and quiet life.
The lyrics in this song are very similar to a 2000 song by Britney Spears called "Lucky" that told a similar story of a celebrity who had all the fame and fortune, but then she was left alone. This is similar to the way that Taylor feels about her own experiences in the music industry and how she feels about herself as a singer.