I do not know how many people came into contact with this one Dr, but at 14 years old he told me my lungs were so bad I would not live past 32 years old. As I was going out his door I heard him say, "UNLESS...", so I turned to listen.
"Unless you start smoking marijuana. It helps thin mucus so it is easily coughed up. It builds up the good bacteria in your lungs that fight illness. And it increases you ability to take and hold deep breaths, thereby helping to prevent pneumonia.
Not everyone that smoked pot was a drug addict.