Meaning, Main Idea of The Song
Have you ever fallen in love with someone? If you're more than ten years old, and normal, it's more possible than not that you have. Or even so many times :). If you have, what did you feel when you saw or met the one you crushed on? I guess you would feel nervous. Your heart would beat faster than usual. Also, I guess you were afraid of doing something, even a very little thing, which could give bad impression.
That's what this Christina Perri's A Thousand Years song mainly tells. It is about deep feeling the singer has to someone. The feeling has actually come for a long time. However, she is afraid and doubtful. She is not confident with herself, just like all of us when falling in love. And so she hides the feeling. Consequently, romantic relationship between them has not been built, even though there's possibility that the one she adores actually has similar feeling to her.
The song also depicts that after hiding the feeling for long time, one day she saw the boy standing alone. And as usual, her heart beat faster. Yet, different from the other days, that day she decided to revealed anything. She was determined not to lose the moment. "I Will not let anything take away" so the line goes. She made up her mind that whatever will happen, she will let the one she loves know what she feels.