After writing my response to him, I thought it worth posting myself as well.
The substantive bulk of my response to him follows:
It is also important to note that the question is "What advice would you give your younger self?". The answers below are specific and personal to me and my life's journey, I don't know how useful they may be to anyone who has not been in my specific shoes. However, I imagine the point of asking this of multiple people to distill some sort of Universal Truth from their collective answers. In this regard, I hope you find this helpful.