I get asked if I am studying (at Uni) all the time. Actually, I get asked what I am studying. Now, I know you can study at any age, but I'm pretty sure they ask me because they assume I am at a student's age. I am 26. I finished my MA two years ago, for God's sake! When I tell my age, they are like 'whoa, really? I thought you were, like, 20 or something'.
That said, I look much older now than I did five months ago. It's not exactly 'older', but experienced. Because I am. I am much less innocent than when I first came to London, on my own. I have learned so much, and the hard way, and it shows in the way I move, talk and relate to others. There's this girl at my workplace, she's 24 and she looks like she is in her thirties. And I don't think it's because of her appearance (although she does look a bit severe with her hair up) but because she has had an admittedly tough life, so she doesn't act like I did when I was 23. She can't afford to do that. I find that happening a lot more in the places I work at now, where people usually haven't been to university, therefore started working full-time earlier, getting married earlier, and having what I basically call an adult life earlier.