Currently existing in a similar state of indecision and uncertainty, I can relate to the general idea, but I think I'm starting to figure a few things out. First, even our elders still have no idea what they're doing. Answers aren't something that come easily, nor are they something that ever stops coming. You can plan all you want, but everyone is, on the most basic level, dealing with life on a day-to-day basis. Even in our basic routines, there are variances that have to be dealt with specifically and uniquely - things you can't plan for. The answers that come are really just "directions," in the end. A general vicinity you feel your life should be aiming for, and you readjust your course in that vague orientation. As you journey, you change, and as you change, so does your direction. There's no "Eureka!" moment that sets everything in black and white. The actual mistake may be believing there is an ultimate goal or purpose for our lives. An "it's the journey, not the destination," sort of thing, if you will. Secondly, time spent waiting and thinking may be more of a requirement than we realize. We feel old because this is the furthest point in our lives, but only so far. Assuming we're smart enough and fortunate enough to continue surviving, we're only going to get older, and though that sounds kind of depressing, it also means we'll have had more time to live and see what works for us and what doesn't. Being fresh out of our teens and with both feet firmly in "adulthood," we may think we're ready to tackle life head-on after the restrictions of youth, but we're actually still young and learning.
The final piece may be to simply not over think everything so much and go with the flow. To put it in the context of this comic, it's all well and good to figure your life out if you can, but if you starve to death because you didn't take a break to go eat, you'll never make it to the future you were thinking about.
Just my take on the whole thing, anyway. Ask me again in a month, and I might give you a whole different answer. So, just take it for whatever it's worth to you.