A more thorough explanation:

Definition: Sound mind and memory refers to a person’s mental state at the time of making their will. It means that the person has enough mental capacity to understand their actions.

For example, if someone creates a will, they must understand what they own, who they want to give their possessions to, and the effect of the will. If they do not have a sound mind and memory, their will may not be valid.

If someone contests a will, they must provide evidence to the court that the person who made the will did not have a sound mind and memory at the time they signed it. The court may call witnesses who saw the person signing the will to determine their mental capacity. If the court finds that the person did not have a sound mind and memory, the will fails.

Example: John is 90 years old and has dementia. He creates a will leaving all of his possessions to his neighbor, who has been taking care of him. John's children contest the will, claiming that John did not have a sound mind and memory when he signed it. The court calls witnesses who saw John sign the will and determines that he did not have a sound mind and memory at the time. Therefore, the will fails, and John's possessions will be distributed according to the laws of intestacy.

Explanation: This example illustrates how a person's mental state at the time of making a will is crucial. John's children contested the will, claiming that he did not have a sound mind and memory when he signed it. The court called witnesses to determine John's mental capacity, and they found that he did not have a sound mind and memory. Therefore, the will failed, and John's possessions were distributed according to the laws of intestacy.