When you get new information, there are two typical responses.
The first is to ignore the new information, acting as if it doesn’t affect what you already decided. If your decision was rational—that is, based on facts and intelligence—then it necessarily was both based on information and subject to new information. If you don’t incorporate the new information into your previous decision, your decision—whether rational at first or not—is now necessarily irrational . You now have no guarantee that your course of action is the best way for you to obtain more joy and happiness.
The second typical way people respond to new information is by ignoring all previous information. In this case, the typical situation is that the new information comes as a surprise and in the context of intense emotion. Intense emotion has the effect of dimming the strength of the mind. In this case, people who are surprised with new information tend to forget the thought process they went through when they made the original decision. New information must be evaluated with prior information in order to make a rational choice.
There is a better way. When you get new information, find your list that you used when you made your decision. Add the information to the list. Try to be as impartial as possible when integrating your expanded view of things.
Be willing both to make a completely different decision and to hold fast to what you previously decided. Both choices are attached to powerful psychological forces that have to be intentionally resisted. When we have made a difficult decision and face opposition, we will be tempted to overweigh any new information that detracts from our decision, because it would be easier (but not better) for us to decide differently than we have.