A central assumption of much of my research is that people can choose their own beliefs. There are many possible mechanisms, but Vrij's discussion suggests yet another. If you want to believe something, just describe the relevant event to yourself using appropriately loaded language. Your memory does the rest.The more we understand our minds, the more ephemeral and contextual we appear to be. Belief is particularly fluid. This adds new dimensions to classic books describing mass movements.
Conversely, if you want to prevent your desires from affecting your beliefs, use measured language to describe it to yourself. Otherwise, you're burying a time capsule of deception for yourself to dig up at a later date.
My approach to creating a selectively-false and happy set of memories is a large collection of family photos that cycle across our array of computer displays. These leverage the principle of selective reinforcement of memory -- given two proximate events, unbalanced reinforcement of one will decrease retrieval of the second. It as though as one memory grows it usurps the foundation of its "neighbor" memories. In this experiment the happy photos selectively blur away all other events.
Truth is fundamentally overrated in our current universe.
PTSD (post-traumatic stress disorder) may work the other way. By constantly reinforcing very negative memories all good memories seem to be subsumed. This is why some therapies for PTSD have been hypothesized to be potentially counter-productive. I think that PTSD research is now focusing on "selective destruction" of memory and reinforcement or implanting of more positive memories.
Memory therapy, involving the selective implantation of false memories for the the benefit of the patient, will be an increasingly interesting subject over the next twenty years. Particulary if it is done without the informed consent of the patient. Of course, some would say advertisers have done this for years.
Speaking of memory, I thought I wrote on this topic some time ago, but my searches aren't turning anything up. Maybe I did that in an alternate time slice :-).