The invoice is missing - cycles of life

My mom lives far away. I left home and my hometown when I was nineteen, which was just the right thing for me to do. My brother still lives nearby. Well, I have to say a good distance sometimes helps to keep a good relationship with family. Still, I try to be a good son and phone my mom every Sunday, and try to visit her once a year, if possible. Her birthday is coming up in late summer, and I wanted to send her a nice present. On the phone she told me her adventure of getting a new memory card for her digital camera at the local electronic shop. So I thought I send her one of those nice digital picture displays, which she can use for the old memory card from her camera. These days it takes about 2-3 days and your gift gets already delivered - thanks Amazon! However, I made one fatal mistake, somehow I missed the 'send as a gift option'. Bad mistake. Three days later I get a phone call from my mom: "Thank you for the present... it is much more expensive at the local electronic shop, but the invoice disappeared----- the invoice is miiiisssiiiing."  What?  It turns out the neighbor brought the parcel, because she was not at home during delivery. She did not have her glasses at hand, so the neighbor looked at the bill and figured out the secret about the mysterious parcel, and that the invoice had been paid. But after he left, the invoice was gone. "The invoice is gone. Do you think he took it?" If so, thank you neighbor, because it should not have been in there in the first place. "The invoice is gone. Do you think he took it?" No mom, you probably just threw it away with the package. "The invoice is gone, but I found it at the local electronic shop and it was really expensive." Sorry mom, the invoice should not have been in there. "It is gone, that never happened to me. Did he take it to order one for himself?" No mom, it is not important anyway. Mom, did you like the present? "Yes, wonderful, but the invoice is gone'. ... it was too much now. I said, mom, if you are so much more excited about the invoice, I will send a few next time. After  a while I was able to get off the phone. ...JEEZ, I was glad that I did not have to listen to that the whole day... old people. I was also glad to learn from a friend that her mom is just the same. Well, my mom is approaching her late seventies, and it just seems to be part of the normal cycle of life. After a while I thought, I better get used to it. I am sure it runs in families and probably I will be just like her in 30 years. Poor kids, though. Well, I guess I am going to phone her again on Sunday to find out whether the invoice is still missing. I am sure she wants to tell me that exciting story again, and I will be good and listen again to the story. After all, it is my mom.