Does anyone understand the "They’re like reformed smokers" comment? > “They’ve gone from printing a bunch of money, like driving a Porsche at 200 miles an hour

Does anyone understand the "They’re like reformed smokers" comment? > “They’ve gone from printing a bunch of money, like driving a Porsche at 200 miles an hour, to not only taking the foot off the gas, but just slamming the brakes on.” I understand the Porsche example, but I don't understand the smoker reference.