"
I guess you heard, I guess you know
In time I'd have told you, but I guess I'm too slow
The meaning of this words is the singer or the man behind this song tells that he guess the girl he loved knows that he love her, but hes too slow to show or tell it to her, because maybe he can't express his feelings because he is afraid that the girl he love may reject him and may tell to him that she doesn't love him. So he make a song to tell to his love, how he feels about her.