(Mark Erelli)      I thought I heard you knocking   As I sprung up from my chair   Flung the door wide open   There was no one standing there   It's getting harder every moment   To tell what's really real   Sometimes it ain't the things you know   It's more the way you feel      I thought I heard you knocking   Tapping soft and light   Like the sounds an old house offers   When it settles for the night   You used to be just as familiar   Like whiskey on my breath   Now whenever you come calling   You scare me half to death      Haven't you already had your fun   Or maybe this has only just begun   You got me wondering should I stay or should run   Won't you tell me what you think it is I done      I thought I heard you knocking   Like a hard rain tumbling down   When I strain my ears to listen   I can scarcely hear the sound   Some questions they have answers   And you never ask again   Some questions only lead   To places you've already been      It's such a dark and bitter seed you've sown   I've got a worried feeling deep down in my bones   If I look at you will I just turn to stone   I don't know why you won't leave me alone      I thought I heard you knocking   Sharp and shallow on my door