Oak is the remedy for strong, steady people who never give up under adversity. They plough on with determination, and never consider resting until they are past the point of exhaustion.
Oaks often have many people relying on them, and their sense of duty is strong. They may feel frustrated and unhappy if illness or exhaustion mean they are forced to do less than they wanted.
So much is positive about the Oak person, but the negative side is the stubborn refusal to rest or sit back when the need for rest is obvious. The remedy is used to help us remain strong in adversity, while at the same time we learn it is better sometimes to let go rather than crack under the strain.