Writer Douglas Adams, author of the book, "The Hitchhiker's Guide to the Galaxy", tells a great story about jumping to conclusions about people.
Once Adams was sitting in the waiting area of a railroad station and had placed a package of cookies and a newspaper on the table in front of him.
A stranger sitting next to him suddenly reached across, opened the bag of cookies and started to eat them.
Adams, annoyed, said nothing, but calmly took a cookie from the bag as well. Soon the bag was empty as the men both ate from it.
When the stranger left for his train, Adams picked up his newspaper - and found his bag of cookies underneath it. Rather than a stranger eating his cookies, he'd been eating someone else's.
Teachable moment: look to yourself first before you assume anything of another person. "Otherwise", as Adams quipped, "you'll wonder why it seems that someone else is eating your cookies."