Chinokanganwa idemo, chitsiga hachikanganwe.

Definitions

chitsiga: tree stump

Translation

The axe forgets but the tree stump never does.

Application

The offender easily forgets, but not the offended person.

The offended person may later bring up the matter when the offender has long forgotten, sometimes even seeking revenge. Their actions may then be perceived as irrational or unjustified simply because the offender no longer remembers the incident.