The entirety of high school happened at 15. At 15 I had my first boyfriend who gave me my first kiss, and my second boyfriend who fucked me. I have begun to summarize the experience with the phrase, "I didn't lose my virginity voluntarily." Which is both much more and much less than what I remember.
At 15 years old, I was a liar. I lied mostly to my parents, who I believed (as all 15 year olds do) were intolerably strict. Now that I write this I cannot remember any specific instances of lying to someone other than my parents. But I am convinced: I lied. I learned to consider all possible answers to any given question. I am afraid, sometimes, that I have irretrievably lost my sense of truth, that I may be a liar.
I went to college at 19, spent four years there, and left at 19. It was the beginning of my adult life, although I have spent the entire time since then denying all evidence of adulthood. I tell people that at heart I am still 19, on my own for the first time and realizing that I can eat cereal with ice cream for breakfast and no one will stop me.
29 was my ten year mark. At 29 I could start to say that I've been doing something, or not doing something, for ten years. It makes for a clean story. I am still telling it. I am still 29, even though part of the mystique of graduate school was that I would graduate at 30. That isn't the story anymore. I started, I will finish, at 29. I think this may be why I have such a hard time acknowledging my birthday. It's not that I don't want to be 30, but because I am already rounding my experiences to fit the story. I know that when I tell these events later, they will begin with the phrase when I was 29.