I'm interested to know economic justifications of forgetting in various fields.
On example is Green and Porter(1984). To sustain a Cartel, Cartel members have incentive to forget deviations in a sufficiently distant past.
Another is Ekmekciy(2011) which shows that a rating system works better if it stops publicize misconducts, once they're old enough.
Literature on a more abstract level is also welcomed, e.g. results like it's more socially desirable in a dynamic games, some agents are restricted to stationary strategies.