People who see sweet potatoes may seem stubborn. When things don't go well, they may be obsessed with identifying the root cause. This type of person seems to be serious and perfectionistic. They may have a strong belief that things must be done perfectly and precisely. They often cannot delegate to others and tend to tackle things in their own way or with their own plans. To accomplish things perfectly, they believe that it is necessary to push through with a firm will. The feeling that only half-hearted efforts result in only half-hearted outcomes may contribute to their stubborn nature.