Since you want to talk about "selfishness," let's see how "selfish" you are. Do you regularly exceed the speed limit? Do you eat foods that may/will contribute to more visits to the doctor? Do your consumption patterns meet the standard of selflessness and modesty or do you take advantage of your relative wealth to indulge in stuff that, truth be told, you really don't need? For instance, do you purchase things made by essentially slaves in third-world or authoritarian countries? When is the last time you actually sacrificed something other than some change for the least among us? What were the circumstances?
In any kind of reasonable standard of selflessness, you and me and most here probably won't fare too well. There are a whole lot of externalities flowing onto others from the selfish behaviors enumerated above, and there are many more from where those came.