- someone from your immediate family lost their phone (or it ran out of battery) and they're calling you from a borrowed phone
- someone close to you had an accident and police / hospital is calling you about it
- a call from school about your kids
- someone you know changed their number
- delivery person has a package for you and wants to confirm you're home
- you bought something online but they ran out of stock and want to offer you a replacement
- etc.