Walk straight, my son - as the old crab said to the young crab. (Irish)

We'll never know the worth of water till the well go dry. (Scottish)

When a twig grows hard it is difficult to twist it. Every beginning is weak. (Irish)

When fire is applied to a stone it cracks. (Irish)

When in doubt, do nothing.

Where the tongue slips, it speaks the truth. (Irish)

Where there is no trust there is no love.