To me, that question was never relevant. When I was a teenager writing Ascension, time is frozen. I thought I'd never be older than a teenager...maybe I was in that vampire mindset a little bit too strongly. But at that point in your life, it's just hard to imagine being older than you already are, dealing with what we know call "adulting." I was fully ready to join Cheyenne in aging as slowly as possible, though I had no desire to take on her gargantuan problems.
In college, it wasn't even really that much different. Despite all the growing you do in higher education between the years of 18-22, you're still very connected to your teenage self. I can still feel very clearly the teachers who told me I wasn't reaching my potential, the first time I put myself out there to a guy and was turned down, the first time my friends betrayed me, the first time I really fought with my parents. The young adult years are a time of drama, of heightened emotions.
But even now, barely 22, I'm able to look back and see how absolutely dramatic I was and wonder exactly what I was thinking. So now I have to start asking myself--how do I stay connected to that part of myself to still be able to write young adult fiction?
There's two parts to this answer. First part--Cheyenne's voice lives in my head. I don't plan what she's going to do; she just does it through my keyboard. So she makes it easy.

But I realized this past weekend that I have still definitely held onto the child in myself. Yes, I am a young adult who's becoming more of an adult and less young as the days tick by. But my childhood is still fresh, my teenage years are clear. I have no shame in loving disney, in sleeping with a stuffed animal, or enjoy running around blowing bubbles with a giant bubble wand or wearing a paper flower crown on my head.
This is something that everyone should tap into though, every once in awhile at least. Being a kid is wonderful and difficult all at the same time. There's nothing wrong with tapping into that sense of wonder and innocent fun, abandoning your "adulting" abilities one day to fly a kite in the park, re-read your favorite kid's book even if you don't have kids, or just spend a good hour blowing bubbles and trying to catch them. If you need some help tapping into that mindset, just pick up one of the many wonderful children/middle grade/young adult books in the world now. They're totally immersive and will send you reeling back into that dramatic, wonderful time of your life.