To dream of finding something new represents feelings about new ideas or new insights you have discovered. Solutions to problems. Feeling lucky to discover something. Discovering a secret.
To dream of finding something lost represents feelings of something in your life not working anymore. Jealousy that you will be embarrassed if something in your life doesn’t work easily. Your inability to come up with an idea to solve a problem.
Example: A man dreamed of being unable to find something. In waking life he was unable to find a solution to a problem and it bothered him.