Hearing the song, and seeing what other posted about the music video I feel like they go hand and hand. To me the song is about the guy/girl loves this girl/guy but never really got the chance to say I love you. And when the chance came, it was too late. "what hurts the most is being so close and watching you walk away" saying that it hurts more watching the person you love with your whole heart walk away from you, without the chance of telling them how you feel. Or being so close to it, but you still can't say it, and the person that wants to hear the words get tired of waiting for you to say them. So they walk away.