In myasthenia gravis if you've never had a resp. crisis does that mean you never will? or just been lucky so far? thus my greatest fear! anxiety! help

Unpredictable: It is not easy to forecast outcomes in myasthenia gravis, but a prior thymectomy is in your favor, and a relatively benign course supports future stability. Although odds are against a myasthenic crisis, there is no guarantee, but you certainly can shorten odds by taking appropriate medication, and working closely with your neurologist.