I had one friend imply that we all get joint pain as we get older and I shut that down. He didn't mean to be hurtful and after I explained he never said something like that to me again. My friends and family don't question or downplay my pain, fatigue, or photosensitivity.

My husband also has a chronic illness (T1D) so he never shrugs me off. It's weird to bond over chronic illness but ever since I was diagnosed he's been really understanding and kind, and even though his illness is different he can empathize in a way other people can't.

All that to say, I don't think you should accept other people downplaying you experiences with this disease as normal. It's not okay, and you are fully justified in shutting that sort of nonsense down. If they're good friends they'll listen and, even if they don't understand, will at the very least stop that behavior. People who love and care about you will be respectful of your feelings.