welcome jw, you're right it's different for everyone.
i have had to deal with cognitive issues but then i detected and corrected my zinc deficiency and things cleared up.
you can do things like a niacin flush, or take ginkgo biloba, to increase blood flow through the brain and stay hydrated.
here's how debilitating my cognitive issues were. i was still getting up and going to work each day, and doing a good job, but i had a lot of trouble driving. i could not process how things were moving around me on the road. i would sit at a deserted 4-way stop and try to cross, unable to decide if something had appeared from one direction while i had glanced the other. it was really hard to drive on the highway and assess if it was okay to change lanes. i could never remember if i had locked the door, at home or when leaving the car. i easily lost track of conversations. if watching television, i could not remember what show i was watching when the ads were on.
no-one around me could tell. i was telling my mother about it all the other day and she had had no idea. and, when i was taking courses, i was still getting great marks (don't ask me how!).
i started being really dedicated with nutrition and everything cleared up. especially when i took ginkgo, i noticed that i never lost track of a conversation no matter how many times we digressed onto side topics. it was pretty sweet
just recently i noticed i was a little foggy on whether i had locked the door or not. i don't have a lot of money at the moment so i had run out of a few key supplements. i just had to stock up and get disciplined again and things are on the mend.
i spent 15 years depleting my body's nutrient stores, via being a strict strict vegan. i am only 5 years into building those stores back up, so i still have to eat very properly and supplement at therapeutic levels to stay on top of everything.
IMHO there are more than 4 categories of MS - it's not a real diagnosis it's a checklist of symptoms and signs, and it's up to patients as individuals to unravel our personal etiologies.
TIMS is a great support resource, welcome, and happy reading