mails this question and I read the words and think, “I don't know.” Who is a senior? Not Kate. She's in college. And not Ellie. She's a freshman. Is this a trick? A test? Why is she asking me about seniors? I e-mail her back a big question mark. A while later - it's always a while later - it occurs to me that maybe my daughter is asking who is a senior, as in who, according to AARP, is over 50 (although movie theaters, department stores, and a zillion other places have varying senior ages). Maybe she's asking this question not to trick me and not because she's in search of a baby-sitter but because her friend, April, is starring in “She Loves Me” next week and I'd mentioned that I needed three tickets. So I e-mail her again. “Do you mean ‘senior' as in high school or senior as in discounted tickets?” Sure enough, when I check back online, there's her e-mail, which says, “Tickets.” It's so obvious in hindsight. I should have known immediately what she meant. But the word “senior,” as in senior discounts, simply didn't register because, I swear to God, I forget that I'm a senior and that many of my friends are seniors, too. I forget I'm not who I was for more than 50 years, a kid, a young adult, an older adult, suddenly different now, a separate category, a whole new demographic. And I am therefore continually surprised when I get a discount on movie and theater tickets and clothes and admissions and even cups of coffee without ever having to show an ID. The truth is if I close my eyes for a minute, and even if I don't close my eyes, I can see - the picture big and clear as a new 50-inch plasma TV - the senior I was, in high school, in the spring of 1964. In my school uniform, an ugly, blue-plaid thing, saddle shoes, too, young and fresh-faced, but finally grown up, I thought. I knew. I'd been accepted to college. I had a date for the prom. And a part-time job. And a $50 car my father bought just for me. And my whole life, just like the world, was bursting to bloom. And I wonder, how can the word “senior” apply to both then and now? As for the discounts: I wanted them desperately when I was 13 pretending to be 12, hunched in line at the Randolph Movie Theater, no lipstick, no mascara, either, because who wants to pay 25 cents to see “Attack of the Giant Leeches” when you can pay 15 cents and have a dime left over for a vanilla Turkish Taffy and Bit O' Honey. All the kids did this, pretended to be younger than they were. Even Rosemary, though she'll deny it, and Diane and Janet and Ann Marie, every one of us in such a hurry to grow up. Except on Saturday afternoons when the smell of popcorn intoxicated us even more than the scents of Ambush and Heaven Scent, which we all wore. Now we are grown up, long grown up, and routinely stunned by this fact. Stunned when we do the math and note how long we've been out of school. Stunned when we tell people how long our children have been out of school. Stunned when we fill out a form and check off our age group. Stunned when we look in a mirror. My daughter phones. “You never e-mailed me back, Mom. So how many senior tickets should I get?” “How old is a senior?” I ask. And she tells me 60. Three, I say, “All three.” And like the spunky little girl selling movie tickets at the Braintree Cinema a few weeks ago, who didn't look twice before giving me a senior rate, my daughter doesn't pause, either. She doesn't say, “S--- is senior, too? And B----? I didn't know this. I thought they were younger.” They aren't and she sees this. Maybe the whole world sees this. But I look at them, and I look at me, and I don't. __