'Amnesia' is a mass noun, so do not put the indefinite article before it, or before the modifier preceding it.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Hotmale Thanks. But "dinner" doesn't take the article either, unless the noun is modified, e.g. We had a delicious dinner.In that sentence, dinner is not a mass noun, but refers to a kind of meal..