if you haven't been using opiates before or in a long time and don't have much of a tolerance -- and it sounds like you haven't/don't cause 20mg of hydrocodone gave you so much pleasure-- than you can do the same thing again tomorrow if you want. i mean if it worked like it did this time than your tolerance is way below that level. one time doesn't raise your tolerance like crazy. but taking them like that daily, will build up a tolerance a lot faster than if "you wait a week."
i'm assuming you took 4 pills of vicodin, just be carefull with how much you take, especially because vicodin has APAP in it (the liver killa). you can get sick, have to go to the hopital and explain what happend ("abused a painkiller"), if it's not too bad they'll fix you up, but it'll go into your medical record forever.... have a good time after that trying to get pain killers from any doctor, they won't be liberal with them.... and your friends will laugh when you tell them that you were in the hospital essentially because of tylenol poisining...
-each person is different but in general your liver really can't/shouldn't handle more than 4grams of APAP MAXIMUM in 24 hours... a lot of people get sick taking a lot less.