If they have fufilled their dreams. Have they gone as far as they thought they would, or have they come short? There are some dreams that they never thought they would reach. Those are just false dreams, like false ribs, and that they are normally an impossibility. But the realistic dreams, were those met or did they fade?
Some people dream to become an actress, a millionaire. Those are false dreams that can become true. But the more realistic dreams would be to have a family, own a house, live on a boat, get a master's degree, learn a new language, become an author, etc.
And an important factor is that dreams can always be born, at any time in your life. If you are 40 and wish to go somewhere, that is a dream that can be met.