Are we really at the point where a 30 year old can offer sage advice on living life? Wow. As a counterpoint to "be the best you can be in your profession": https://www.youtube.com/watch?v=hIJdFxYlEKE [PyCon keynote by Jacob Kaplan-Moss on 'mediocre developers'].
Even the people who haven't accomplished much can still have worthwhile things to say about life. My father's had a hard, hard life. His advice isn't really good in terms of success, but rather as a "don't do the kinds of crap I did" sort of thing. Our lives are different enough that little of it is actionable, but I still listen to it, even if he thinks I don't.