Modern advances in transportation and communication have changed many of the basic ways humans live together, by giving people the ability to move and speak long distances with ease. For much of history a most human society was composed of small tribes or towns. People rarely left family and friends behind. The people someone interacted with and saw everyday were the people he had known his whole life.
This is no longer the case. Today the adult American moves many times in a lifespan, and lives far from his extended family and old friends. The people he works around are not the people he lives near, and neither his co-workers or his neighbors are his friends. Our American ideal of "individualism" teaches us that, despite our loves and friendships, life is essentially a solitary act. Our modern cities are usually not large communities, but places where thousands of individuals live in isolation. TV and entertainment distract us from spending time with each other. Instant communications allow us to connect with those we know who are thousands of miles away, but it also allows opportunities to hide ourselves. Long ago an isolated human was an exception; now isolation is the rule.
The isolated modern man can become a master of disguise. He can hide his pain, his failure, his disappointments quite easily. He can present different versions of himself at work, at home, with neighbors, in church, and to distant family and friends thousands of miles away. This is something people years ago who were rooted in tightly-knit communities could not have done very easily. The isolated individual at first embraces this isolation. It protects him from showing his weakness and flaws to others, but before long he realizes that there is no longer anyone who knows or understands him. Before he knows it he has descended into loneliness and despair.