Based off the most recent music video as well as the lyrics themselves, it sounds a lot like a relationship that had fallen apart, which is shown in the line in the chorus that says "I let you in, you left me out". But there is also a theme of loss that you can hear throughout the song like the line that says "Truth be told I can't believe you're gone" and "Now I have to face the fact that you're never coming back" and in the bridge towards the end of the song that says "I see you in my dreams, I can't believe you're gone". At the end of the video you see the man bringing what is likely an apology note to the grave of the woman along with a rose which signifies a sort of emotional attachment that you would see in a relationship.The ending scene gives us a better idea of how she died when she appears to get hit by a car.