To see young people in your dream indicates a fresh outlook on your life. It may also represent a more youthful aspect of yourself. Perhaps you need to be more playful and carefree.
To dream that you are young again indicates that you are behaving childish or immaturely. Alternatively, it represents your failed attempts to rectify past mistakes. You are dwelling too much on past regrets and lost opportunities. It is time to move on toward the future.