We can lessen our losses if we managed to practice what we plan before we engaged into it, but like you said human errors happened whenever we failed to follow our own practices, but if we can limit our sessions and the amount that we are using is decent enough of our spare then it's not going to be hard if we wanted to stop and move forward and forget whatever the amount that we've loss.
When it comes to forgetting some of my losses, it always depends on what amount is involved in the stake. Forgetting my losses has to do with what that stake meant to me and what was the intent behind it while making the bet. It wouldn’t matter much if the sum is somewhere around the surface, not something too deep that I can’t afford to loss, it just passes away by the hour.