When your choices prove to be correct, you "look back" and feel you did the right decisions. When you had made choices that proved to be not too perfect, then some people look back to regret what they did. In either case, you are making choices based on the available information at that particular time. When you are continuously updating yourself with new knowledge, if the choices you made needs changes, you should be able to make them without hurting other areas of your choices. For instance, lot of students make a choice to pursue a particular speciality in college, but by the time they finish college, some courses may not be good enbough to find a job because the other circumsances have changed.