Phobias are irrational fears. They can be of objects (e.g. snakes or mice), experiences (e.g. visiting the dentist, being in an enclosed space), or ideas (fear of the number 13). Famously, former Arsenal striker Dennis Bergkamp had a phobia of flying, refusing to set foot on a plane, and had to travel to away matches in Europe on long road trips that often took several days – how much simpler would his life have been had he managed to conquer this fear?