This can be used even when playing sport and you only win by one score. Aswell as when you go to a fast food restrant that often makes mistakes with your order, but thay get it right first time. It is a statement or decliration stateing that you only had to try something once and then the task was completed requireing no more effort.
Tony "I all ready did, one and done"
Tom "Out of sight"
Ted:"Man I wish I could go out tonight and pick up some strange but the wife is up waiting with the kids."
Bill:"Screw all the drama, taking care of kids, expense and sexual monotony a relationship is..I'm a one and done kind of guy!"