Regarding letters about waiting in line at the post office: Modern technology can save a lot of time, but it would be a shame to eliminate lines (at the grocery store, airport, post office, etc.) altogether. That is where you can observe and interact with people and practice patience, kindness, etc. Busses are another good place to interact with people.
One of my favorite experiences was in a line waiting for a bus in Amsterdam. A man gave me one of his tickets since I didn’t have the right change. I learned more about this caring human being on the half-hour ride to Haalem and it made my trip even more special.