Being a seasoned Londoner, Martin gave the body the "London once-over" - a quick glance to determine whether this was a drunk, a crazy or a human being in distress. The fact that it was entirely possible for someone to be all three simultaneously is why good-Samaritanism in London is considered an extreme sport - like BASE jumping or crocodile wrestling.
This is a world of unhappy beings. They don't understand how simple it is to be happy. You just have to practice meditation. To meditate is to be happy.