What Song Does Tim Mcgraw Have About Taylor Swift?

I think it means her boyfriend and her just have 1 summer left together till they go there separate ways and she moves so she tells him when he thinks of tim mcgraw he will go back to the memories they had together that summer, then she wrote a letter for him she never got to give him so she goes back to her home town and leaves the letter at his door step telling him how much she loves him.