It is difficult for a non-MSer to understand the effects that MS bestows upon us. Try and explain as much as you can, but don't stress yourself worrying about it because it'll only negatively affect your body.
Try and explain it in simple terms, this is what I used to explain to my family/friends (don't laugh
1. Brain fog feels as though my brain is wrapped in cotton wool and no thoughts can enter my brain because it's already occupied by the wool.
2. Chronic fatigue feels as though my body is about to shut down at any minute and I can no longer process a thought and I must sleep now now.. NOW!!
3. Numbness and tingling is like having pins and needles - but for weeks and much more irritating.
4. My speech isn't perfect because it feels as though my tongue is too big for my mouth.
5. Please understand if I tell you to be quiet during a conversation - I can no longer process what you are saying to me.