The people participating in the study had to recall a number of events in their lives, both positive and negative. For each event, they rated the emotions that they felt at the time it happened, and then the emotions that they felt in the present when remembering that event.
The authors found that every cultural group included in the study experienced the FAB. In all of those sampled, negative emotions associated with remembered events faded to a greater degree than positive emotions did. Interestingly, there was no evidence that this effect changed with people’s age. The FAB is a lifelong cognitive bias, it affects young and old.
The conclusion is that our ability to look back on events with rose-tinted glasses might be important for our mental health, as it could help us to adapt and move on from adversity: It only makes sense to enjoy the positive benefits of pleasant experiences and to limit our potentially traumatic recall of unpleasant experiences. The authors suggest that the FAB is part of a set of cognitive processes that help emotional regulation and aid psychological resilience.
If you want to know what went wrong, better check the written records and formal notes taken at the time. Chances are most of the people involved in the project will have a version of the truth coloured by the FAB which may not reflect what really happened. If you are involved in a project that did go wrong, get the facts on paper as early as possible, before the fading kicks in.