"When riding a motorcycle, the brain of the rider is stimulated. Differences in brain use and level of brain stimulation can be observed in motorcyclists who ride regularly and in motorcyclists who have not ridden for extended periods. Incorporating motorcycle riding into daily life improves various cognitive functions and has positive effects on mental and emotional health such as stress reduction". (emphasis mine!)
So there you have it. Leather and ballistic nylon have replaced corduroy jackets with patches on the elbows and cardigan sweaters as the unofficial dress code of the intelligentsia.