On the basis that the greater the emphasis on not doing something the more children are likely to do it, I'd say: whatever else ye do, do not fall asleep...
when I worked as a shepherd, people used to ask me all the time if I kept falling asleep while I was counting sheep. For some reason they all thought it was original.
I've learned to count by threes (for large numbers of sheep count every group of three sheep as one). problem is I can count by threes but I can't multiply by threes.
I stay awake all night because I keep on counting sheep from 1 to 10,000.
Edited by: happyexplorer
For some reason they all thought it was original.
And you hated the stereotype so much you thought of an original username?

Even though we hardly have any sheep in Malta (goats are more common) and fences are scarcer than the sheep, we still count sheep when we want sleep.
However, when we want kids to stay awake we advise they count the holes in a sieve, so that's supposed to have the opposite effect but I don't really think so.