Gratitude

Sara Yoheved Rigler has an article about gratitude on Aish.com which is worthwhile reading.
A couple of months ago, a a mother of two boys approached me to ask if I would tutor her young sons for an English test that they were taking in the beginning of June. In the end, I lent them two grammar books which have yet to be returned.
The family lives across the street from me. I bumped into the mother last week and asked if her children had taken the test. She replied in the affirmative.
"I would love to know what type of questions were asked on the test," I told the woman." Knowing that the boys had a busy school schedule, I asked when I could call them. She said that I could call in the afternoon, since it was Friday and they would be finishing school early.
I called a few hours later and the mother told me her boys were sleeping but she would have them call me. I reminded her that my books were still in her possession and she told me that her sons would return them.
Friday passed with no call or return of the books. Now it is Monday and I still haven't heard from them. I can assure you that when they needed the books, they were at my door at the first available moment.
Let's take more care in returning items in a timely fashion. Let's show gratitude for the favor bestowed upon us. Let me be dan lechaf zechut.
In a similar vein, when someone calls with a suggestion for a shidduch, if you decide that it is not appopriate, at least have the courtesy to call back the person who suggested the idea, thank them and let them know that you aren't interested, for the moment.