Sisu

But Sisu runs even deeper than grit. It is a type of mental toughness that allows you to bear the burden of your responsibilities, whatever they happen to be, with a will and perseverance that is unbreakable. It is the ability to sustain your action and fight against extreme odds. Sisu extends beyond perseverance. It is what you rely on when you feel like you have nothing left.

Failure is an Event, Not an Identity

Most people let their battles define them. They see failure as an indication of who they are. Mentally tough people let their perseverance define them. They see failure as an event. Failure is something that happens to a person, not who a person is. This attitude is what helped carry the Finnish soldiers through the Winter War. Even when surrounded by failure, by death, and by insurmountable odds, their Sisu did not let the soldiers see themselves as failures.