Yes. A few years ago a few friends and I who had attended an American military high school for a while set out to find all the other students from our class. Sadly, we already knew that 18 of the boys had been killed in the Vietnam war.
One of them was a twin and his surviving twin couldn't cope with the loss of his brother, turned to drugs and has been living in a mental institution for the past few years now.
Another, although a top student in the 60s, simply fell on hard times and after living on the streets for many years, he is now a part-time maintenance man for a small company and lives in a one bedroom basement flat in the suburbs of Paris. He barely has enough to live on.
One of my brother's ex-girlfriends ended up joining a religious sect and totally losing it mentally. Her family have fought for years to get her out of there, but without success.
The positive stories outweigh the negative by far, but I do feel so sad for those who have never found happiness in all these years.