(1) Any time in the modern era that predates your conception birthday.
(2) The latter half of the 20th Century; before the Aughts.
(3) The time before email, smartphones and the world wide web.
(4) When your parents grew up.
Before the Aughts, in times of modern antiquity, people had to sit in meetings, pay attention and actually single-task. Can you imagine not being able to text, update your status, or check-in?