New Delhi, July 25 -- Recently, a friend in the armed forces told me he was considering premature retirement. That's not unusual. Many people leave the forces after completing pensionable service to secure a guaranteed pension for life and seek better opportunities in the private sector. What shocked me, however, was his reason. He wanted to retire so he could devote more time to trading.

What followed was a long conversation in which I tried, rather unsuccessfully, to dissuade him, while he, equally unsuccessfully, tried to convince me that he knew what he was doing. We both walked away unconvinced, but the conversation left me wondering: where was this confidence coming from? And he wasn't a one-off. As I explored this newfound addicti...