Dad: “I’m worried about Bill. He hasn’t called since last week!”

Mom: “Don’t worry. I’m sure he’s studying hard at college. Remember, no news is good news!”

If something bad had happened to Bill at college, his parents would probably find out. They would get some bad news. If nothing important has happened, that means nothing bad has happened. So a lack of bad news is a good sign. No news is better than bad news.