The answer to this question is indeed: We don't know - as @ChrisRogers correctly explained. However, let me mention some related research that may help shed some light on the question.
Recently, there have been several highly publicized studies suggesting that psychedelic drugs can be useful in the treatment of addiction. A few of these preliminary studies ...
Possibly of interest:
2011 study from Berkeley, published in the Journal of Neuroscience: Pulling an all-nighter can bring on euphoria and risky behavior: https://news.berkeley.edu/2011/03/22/pulling-an-all-nighter/
I'm not aware of truly "forgetting" as in amnesia, but there have been reports that brain damage can disrupt the behavioral pattern of addiction which I think qualifies as what you describe as what "causes the addict to need more and more to be satisfied".
Naqvi et al 2007 reported that:
with brain damage involving the insula, a ...