I hear the same lament over and over from friends, particularly grandparents, aunts, and uncles who live a distance away. "Why don't kids today ever send thank you notes?" and "I have to call to see if they got the gift, because I never hear about it from them." I honestly don't know if it is worse than in previous generations. My mom and dad made sure I wrote thank you notes. But I also remember when, having heard nothing, they would ponder whether a gift they sent had ever been received.…