Emma Watson, the onetime co-star of the most successful movie franchise ever, is a very grateful and a very lucky person. How do I know that? Because I sat down with the 22-year-old in a gastropub in a trendy neighborhood of North London, and in the course of an hour’s conversation she said “grateful” five times and “lucky” eight. True, of those five “grateful”s two were of the “ungrateful” form — yet these were embedded in clauses like “I felt guilty because I felt like that meant I was ungrateful. . . .” So, as you can see, Watson is a young woman who wants it put firmly on the record that she understands human lives are shaken up in the snow globe of uncertainty, and that simply because she’s ended up being covered in golden flakes, she doesn’t take it as her due, oh, no.

Pale skinned, serious of mien, with tiny little Meissen china ears furled tightly against her tiny little Meissen china head, her brown hair scraped back into a bunch, her meager form lost in a baggy white T-shirt, Watson still looks younger than she is. She’s neat-featured; all the headlines of her face — eyes, brows, cheekbones — seem as if underlined. And it’s quite possible that this rather serious emphasis, all those years ago, alerted the casting director that this 9-year-old girl should play Hermione Granger in the Harry Potter movies, rather than the umpteen thousand others who were gagging, swooning, dying to do so. Oh, and then there’s her mouth, which, in mid-moue, has a top lip that looks sharp enough to give you a paper cut.

But setting her calendar age to one side, Watson’s neoteny affects more than her physical appearance, for she is enfolded in the diaphanous — yet profoundly real — swaths of her former status as a child star. I can’t say I ever paid that much attention to her acting in the Potter movies, but I’ve looked for many, many hours in the general direction of screens upon which Watson has performed spells, mixed potions, ridden magical beasts and generally cavorted about. With four children of my own, ranged over 11 years, the eldest the same age as the actress, and the youngest just 11, I’ve been exposed to a great deal more of the franchise than I would’ve wished. Watson’s performances, per se, aren’t the point here: it’s that I, like no doubt many of you, have grown older while she grew up. When the first movie, “Harry Potter and the Sorcerer’s Stone,” came out, I was a relatively feisty 40-year-old. But when “Harry Potter and the Deathly Hallows: Part 2” finally shazammed to its inevitable happy ending, I was a downright cranky half-centenarian.

So, Watson will always be, for me, a nice middle-class English girl pretending to be another nice middle-class English girl who’s lucky enough to have magical powers for which she’s extremely grateful. That off-screen those magical powers consist of the ability to transform cavorting about into huge mounds of gold — her personal fortune is estimated at $40 million — only goes to prove that we live in a world at least as strange as J. K. Rowling’s fictions. Now Watson has started to cavort in rather more adult vehicles; the first of these is “The Perks of Being a Wallflower,” an indie venture directed by Stephen Chbosky and adapted from his novel of the same name (out next month). It’s a semi-disturbing bildungsroman, set in early 1990s Pittsburgh, about a misfit kid named Charlie, who finds his niche in high school when he falls in with a bunch of like-minded misfits. Watson plays his object of desire, Sam, and she does this with reasonable éclat and newfound maturity. She also manages the difficult feat — for a nice English middle-class girl — of sustaining an American accent. I told her how good it was and she thanked me nicely and explained how she’s honed her vowels: “My grandma said — when I was really young and I’d sing along to the radio — why do you sing in an American accent? I guess it was because a lot of the music I was listening to had American vocalists. And that was something Steve said to me as well: try singing the lines in an American accent. That kind of opened me up. Then I worked with a dialogue coach and I just put in the time to really, really listen and just go over it and over it and over it until I could do it without thinking about it too hard. And I just knew it was really important.”