Which maxim do you remember best from your childhood? | Open thread

A poll put out by the NSPCC has shown that “practice makes perfect” is the maxim that has the most influence on children. A study of 2,000 people showed that three-quarters of adults can recall specific advice given to them when they were younger, and that their parents were the most likely grown-ups to have given them these pearls of wisdom. We want to hear the helpful phrases that you can remember from your childhood. Do you still live by the motto “If a job’s worth doing, it’s worth doing well”? Do you still secretly think that eating carrots will help you see in the dark? Tell us what advice has stuck with you throughout the years.