Dreams are the visions we have when we are asleep. But the word “dream” fills the expressions we use when we are awake.

“The stuff dreams are made of” is a romantic expression. It describes a really wonderful experience.

For example, let’s say you really love flight and space travel. So, a friend invites you to see a launch of a space shuttle. She even invites you to meet the astronauts who are going to fly into space.

After this experience you can say to her, “That was the stuff dreams are made of! It’s a dream come true!” A dream come true is exactly that -- a dream that has become reality.

Let’s make it even better. Let’s say your friend can get you on the space shuttle. You can actually wear a space suit and sit in the flight commander’s seat! That would be beyond your wildest dreams. In other words, even you could not have dreamed up such a wonderful experience.

However, once you enter the space shuttle you feel ill. Your hands shake and you are unable to talk.

The astronauts try to help you. But you freak out, yelling, “Let me out of here! Let me out of here!” When you start throwing the flight manuals around the cockpit, the police come and remove you from the shuttle. It’s a disaster. A nightmare.

After the police take your statement and your fingerprints, your friend tries to calm you down. She tells you that everything will be okay. But all you can say to her is, “I wish it was all just a bad dream.”

But it wasn’t. You are barred from participating in any NASA-related field trips. And now you have a police record.

However, months later your childhood dream of space travel comes back strong. You decide to become a pilot. Your friend advises against it. She reminds you that you have a severe case of claustrophobia, a fear of being in small spaces.

She calls your goal of becoming a pilot a pipe dream. A pipe dream is a hope or wish that is impossible to achieve. This expression began in the late 19th century. Word experts say it refers to a dream experienced when smoking an opium pipe. Those dreams rarely come true.

But you insist it is possible for you to be the first person to fly around the world with your faithful pet cat -- Galaxy. Your friend, however, says, “Dream on!” She could also say, “In your dreams!”

Both of these informal expressions are ways of saying that someone’s idea is a fantasy. Friends can use them in a funny way with each other. Otherwise, both expressions can sound a little mean.

Then your friend uses another informal expression. She tells you to wake up and smell the coffee! She adds that you are living in a dream world if you think you can become a world-famous pilot who flies with a cat. People who live in a dream world are unrealistic. They refuse to face facts.

Your friend’s remarks are hard for you to hear. But you know she is right. So, you decide to write a children’s book about someone who flies around the world with a beloved pet. As you are already a children’s book author, this is a dream that can definitely come true.

For the next few months, you happily daydream about the story you will write. To daydream is to let your creative mind, your imagination, take over. Luckily for you, you can daydream anywhere -- not just in small spaces such as a cockpit.

It turns out you are better dreaming about air travel than doing it. Your book is a spectacular success. With the money you make from your book sales, you are finally able to buy your dream house. And it has a special room just for Galaxy, your cat.

Your proud friend invites you to speak at the school where she teaches. You tell her students to follow their dreams and to dream big. You also tell them that even broken dreams have value. You can always pick up the pieces and make a new one!

That night you call her on the phone to thank her for reminding you to never stop dreaming. She says that is what friends are for.

“Goodnight,” you say. “Goodnight,” she says. “Sweet dreams.”