I understood this song a little differently than what seems to be the majority opinion here but here's what I thought:
He's in a relationship with someone but is just realizing that he should be with someone else. The other person was waiting for him all along and while he didn't know it, he was actually waiting for her too. Now that he realizes she's the one for him, he's going to do whatever it takes to be with her, as shown by the lines "all these words can't waste them on another", which means he's going to end the relationship with his current girlfriend (and therefore not waste his words and time on her anymore now that he knows she's not who he is supposed to be with), and also the line "straight in a straight line running back to you", which means he overlooked his true love when he had his first chance to be with her; but he is now going to be with her with no more interuptions because he can finally see clearly that she is his true love.
I understood this song a little differently than what seems to be the majority opinion here but here's what I thought:
He's in a relationship with someone but is just realizing that he should be with someone else. The other person was waiting for him all along and while he didn't know it, he was actually waiting for her too. Now that he realizes she's the one for him, he's going to do whatever it takes to be with her, as shown by the lines "all these words can't waste them on another", which means he's going to end the relationship with his current girlfriend (and therefore not waste his words and time on her anymore now that he knows she's not who he is supposed to be with), and also the line "straight in a straight line running back to you", which means he overlooked his true love when he had his first chance to be with her; but he is now going to be with her with no more interuptions because he can finally see clearly that she is his true love.