Hobos do drugs. Drugs make you think funny. This hobo did too much, and as a result thought he was a zombie.
Homeless people are usually heroine addicts. Really rich people, like singers or a TV presenter, are cocaine users.
Relaxed, living your life kind of people are cannabis users.
If you do look closely, you'll always see that cocaine, cannabis, and heroine users fall into those respective catagories.