People gain skills by working on hard problems, so it doesn't seem necessary for you to take additional time to explicitly hone your skill set before starting on any project(s) that you want to work on.

The embarrassing truth is I spent so much time cramming stuff into my brain while trying to survive in academia that until now I haven't really had time to think about the big picture. I just vectored toward what at any given point seemed like the direction that would give me the most options for tackling the aging problem. Now I'm finally as close to an optimal starting point as I can reasonably expect and the time has come to confront the question: "now what"?