They have time to be naive. Mistakes or errors in judgment can be made with little consequence. The blunders they make will not render great consequences because at this point of their lives they do not have a lot to lose. I believe that this luxury of having time to make errors and learn from them is the most significant advantage that young adults hold over their elders. It is also a necessary advantage because it is through personal experience that maturity is attained.
Time grants young adults the pleasure of getting to know themselves and their purpose in life.
Not being obligated to a career or a family, they can take a fickle approach to their jobs and their significant others. They are able to experiment in different fields of work in order to find their niche. They are not trapped financially in an unhappy career because they are not responsible for the monetary needs of anyone but themselves. As stated previously, those monetary needs are relatively few. Also, they are able to play the field, so to speak, in order to find an ideal life partner.