After leaving home and starting his first job, David made sure to stay in touch with his mother. They had grown very close after David's father passed away the year before.
David had just moved into his first apartment in the city, far from their village home. He thought that he should invite his mother to the city and show her around. He called her and made plans for her to come to the city on July 7—a Tuesday.
July 7 came around and David went to the train station to pick up his mom. Strangely enough, she didn't show up. David called her and asked what was going on. She said, "Oh, my goodness. I checked my calendar, and it said July 7 was a Sunday! I'm sorry dear. Can you come back to pick me up on Sunday?"
Of course, David didn't mind. However, he did worry about his mom, who had always been good at remembering important dates. Was she starting to lose her memory? He asked, "Mom, how did you confuse the date? You said you looked at your calendar...?"
"Yes, dear. The thing is, I'm still using last year's calendar. I know it's silly, but it's the last thing your dad gave to me before he passed away. When the new year came, I didn't want to throw it away. I've missed a few appointments (约定) here and there, but I don't miss them nearly as much as I miss your father."
