If you lived in a vacuum, your choices would achieve your goals, however, since you live amongst people and since you cannot control their behavior, logic does not always work. There have been many situations where I made all the ocrrect, logical choices and things turned out very differently from what I had planned. The truth is, you can never take every possible variable into consideration. This world, people's emotions, thought and behavior patterns are all chaotic, so unfortunately, logic does not always achieve the goals you want. There are always elements of luck, of consideration, of emotion, of preferences and differences that can affect any outcome.