In the land of letters, you never fall out of touch. School chums, kindly teachers, the stern-but-sympathetic father of an ex who got you your first job in the accounts department. Old colleagues, old neighbours, old flames. You never lose track of their places in the world because their missives fall incessantly upon your doormat: daily from those with lots to tell, monthly or yearly from the settled, sedentary folk. All the correspondence makes your wrist ache.
Over time, the letters stop coming. In the end, if you are lucky, or unlucky, you have nobody to write to but yourself.