Its about wrestling with a problem ... you mentally wracking brain trying to figure why, how, when and what and the thing is the problem is so deeply ingrained that your subconcious is awake and telling you to figure it out even though you know the outcome is already decided and you cant change it so you have to let it go. Having said that "putting the old horse down" is a cowboy term for shooting a horse that can't be ridden anymore so to contextualise it the singer has to end whatever situation has got him bothered because whatever it is doesnt work anymore.
Its about wrestling with a problem ... you mentally wracking brain trying to figure why, how, when and what and the thing is the problem is so deeply ingrained that your subconcious is awake and telling you to figure it out even though you know the outcome is already decided and you cant change it so you have to let it go. Having said that "putting the old horse down" is a cowboy term for shooting a horse that can't be ridden anymore so to contextualise it the singer has to end whatever situation has got him bothered because whatever it is doesnt work anymore.