Dad had it. He also suffered from exposure to Agent Orange, if that helps.
Odd that you note a military connection. As an ROTC cadet doing my advanced camp at Ft. Bragg in the summer of 1990, a fellow cadet woke up one morning having lost control of the muscles on one side of his face, and was later diagnosed with MG. About 6-7 years later, I was in Korea, and an aviator I lived with in my BOQ was also diagnosed with MG after starting to experience blurry vision. In both cases the onset of noticeable symptoms was quite rapid.
If it's any consolation, I have an aunt who was also diagnosed with MG in the low severity range. She's 96 and about as active (and ornery) as you could expect anybody to be at that age.