A nasty hangover is your body’s way of saying, ”you idiot!, so you thought you could poison me and get away with, now it is my turn to have my revenge”. On a serious note though, that is exactly what happens to someone that has consumed excess alcohol and drugs. Our bodies can take so much and no more, and once it has reached the limit of its potential, then that is where it draws the line, by making you feel like you were ran over by a truck after a party, is one way of getting your attention.