Read the following context and choose the best option to answer the question.
Context: Sometimes I called myself , but not often enough . Mary would always say , " Let me get Bob , he will be so pleased that you have called . " The last time I called , within the past year , Bob knew who I was , but could not remember any of the facts he used to so quickly retrieve from his mental archive . We still had a very pleasant conversation , after which he said , " I have to write a note for Mary while you are on the phone to tell her you called .
Question: Why is the narrator surprised by Bob ?
Options: 
- Their recall is going .
 - None of the above choices .
 - Their love of Mary is going away .
 - Their wife Mary is going away .


Their recall is going .