The second time (in the last 3 years) I've reached into the...

The second time (in the last 3 years) I've reached into the cupboard for the Relenza early after flu symptoms (the beginnings of an aching neck, back etc) and again, within 48 hours, the symptoms disappeared.

The one thing I did not do both times (which I should have), was to finish the course after the symptoms disappeared.

Maybe it wasn't the flu - all I know is that whatever it was, it disappeared.