"So what do you do on this scary, lonely, exciting path? That’s totally up to you — you are empowered to figure things out on your own."
It seems like at 18 (or 21, or 35, or 60), everyone is telling you how much time you have to figure things out. I never bought that anyone really meant that when they said it. I don't begrudge them. It's the "right thing to say" in those obligatory moments of insight an wisdom asked of us without consent as though we know what the $@&! we're doing.
Leo Babauta's response hits less on the "what to do" as on the "who to be" of the question, which is the part I've always been a bit more intrigued with.
Also, he's awesome.