Ha. I'm older than you and we did not do them.
The Civil Defense handbooks I picked up at a county 4H fair explained it thoroughly and succinctly.
"If you're at point of impact, you've had it"
Really? We did them all the way up through 3rd grade. Even after the wall fell. I remember our principal telling us that even though the Soviet Union had fell, it was still possible for them to nuke us.