Think of it this way, would you envy someone who has Diabetes? AIDS? Cancer? No, those diseases suck. It might be a part of who you are (as in, "you have cancer") but it's not part of your identity. Your identity is something that defines you and I'm sure that someone with a disease would not want to be defined by their disorder (I
am a wolf and I
have bad allergies, but my allergies aren't part of who I am; I just happen to suffer from them).
It's one thing to use your disease to explain things online, or to let people know you have it, but as @
DustWolf that is not the same thing as being a "migraine therian". Therian is part of your identity, your disease is not. Nor is it something cool to be envied.