In sixish weeks, I’m turning 40. It’s just a number, right? I’ve never been the type to get worked up over age. Maybe it’s because I was always the youngest growing up. I was the last to get her license, the last to turn 18, the last to turn 21. It’s funny how your attitude shifts from “finally!” to “already?” Turning 30 didn’t faze me. I laugh along with the “getting old” jokes among my friends. Even after experiencing the kind of loss that permanently rearranges your relationship with time, I’ve still seen my birthday as a reason for celebration. I’m acutely aware, painfully aware, of how fortunate I am…