Basically kelly or this person in the song has been through some very hard relationships and general hardship in life, this person has always been there supporting her but she has just been oblivious to it. And then she finds love in this person when they help her to see who she is and makes her realise life aint so bad after all. Or when she thought there was no hope of finding love again or a relationhsip where she wasnt used and abused. And she can hardly believe she has found this person, or rly the person has found her.