The same thing sorta happened to me. I think I look older, but still younger than my actual age.
People still mistake me for a teenager, just less than they used to. I used to get carded all the time for anything you needed to be 17, 18 for and I haven't recently. Then again when I go to the deli near work and buy a lottery ticket here and there, I'm in professional wear so that has something to do with it.
At the gym some people recently thought I was about 15 or 16, but I've had others guess closer to my actual age.
People still think my younger brother is older than me though