I think your more likely to carry a scare through from their last life if it was something they were really ashamed of. Everything I have read have been from people who were horrible in their last life.
One women was born with a defect that affected her muscles in her right shoulder and arm, turned out she had been a famous gladiator who specialised in lopping off heads. Hence in this life, she 'fixed' the likelyhood of her being able to do it again by imposing this 'defect' on herself. Once she realized that this was what had happened she regained the use of her arm, though she had a lot of work to do because some muscles had atrified due to lack of use! It was interesting, as I have read other things along this line of things.