Don't ask advice from someone who can't figure out his own life. Rather look for inspiring and happy people.
On another note, why do people for centuries find solace and wisdom in the Psalms? They are written by those who are plaintive and suffering, who feel lost and beaten down and betrayed. They would be not considered "happy" people, and thus according to this axiom offered to never consult others who do not have their own lives figured out, would not be anyone to consult for advice. The Psalms are so very poignant for the very reason they were written by those who suffered and were "unhappy", who saw those people who seemed "happy" and always had things going their way, but yet could not relate with them. Of course, these lowly ones in their sorrow and turmoil and difficulties, turned to the Lord, their Rock and Comforter and Adviser. I submit that highly effective people--women, men, children alike--live in truth and reality and seek help from God or those who are close to God. Those close to God may often be the ones who seem the worst off and struggling, but who cling to God and turn to Him always. That, perhaps, is the difference, and the sign-post of who we should be consulting and turning to: first God, and then those who know and love God and live the way of the cross. And, that is not going to seem all that "happy". It is enduring faith, though, that marks them. Not happiness.