Neurologists and psychiatrists admit they still don’t fully understand OCD or how it works. The condition can’t be cured, but it can be managed, dialing down the barrage of obsessive thoughts — and the compulsive behaviors or physical tics that briefly relieve them — so they aren’t so overwhelming. And for reasons that also aren’t fully understood, some highly trained athletes and performers find that being onstage or on the field, in front of thousands of people — an environment most people find highly stressful — actually reduces their anxiety.