I have a good friend who was recently diagnosed with MS. Just by looking at her, you’d never know anything was wrong with her. She’s perfectly capable of driving, and, most of the time, she’s able to walk around with no problem. But, she gets fatigued very easily, and is subject to bouts of weakness where she has to sit down. She doesn’t ride a motorcycle, but if she wanted to, she’d be physically perfectly capable of doing so. On the other hand, walking across a parking lot from a remote space, especially on a bad day, could exhaust her.
My mother also had MS. When I was young, her condition was much like my friend’s is now. She drove, went grocery shopping, ran errands, took me to appointments, etc. All the normal day-to-day stuff anyone else would do. But there were times she just had to sit down and rest. Regardless of where we were. Being able to park in a handicapped spot near her destination vs. parking in a remote spot in a big parking lot could easily be the difference between being able to walk to and from her car in one go vs. having to stop in the middle of a parking lot to sit and rest. She didn’t ride motorcycles, but, again, at that stage of her disease, she certainly could have physically.