Update B: generally speaking, unless you are doing something 'clever': "a dollar on the left means a dollar on the right".

When subscripting an array or a hash the leading character (sigil) does not indicate the type of the container but the type of the value. The braces {...} tells perl that it is dealing with a hash, the sigil indicates the context of what is inside the braces.

Whoosh! (sound of slices passing over your head)