On the topic of words, one take the idea a step further, considers how different words hold different meanings for different people. Take the word "father." Now, someone who's grown up in a loving home with a loving father will look upon that word with a positive outlook, whereas another may have grown up with an abusive father and think negatively when they hear that word.

I think that's another reason people have a hard time expressing exactly what we mean to someone else, especially when relating specifics in dreams, because we each have had different experiences and no one can see the exact same thing as another.