I have good genes in that both my parents looked a lot younger than their actual ages (especially my dad) for many years. They both turn 70 this year, &, while neither looks 70, they are both starting to look older to me & more... I guess... "frail" - but they're both coping w/ different medical conditions too, which, I think, adds to how I'm personally starting to see them. Neither has completely gray hair though - their hair would still be considered brown & not gray.
Anyway, w/ their genes, I've always looked younger than I am as well. I'm also petite w/ blonde hair - so I think that adds to me looking younger than I am.
When I was younger, I absolutely HATED people thinking I was younger than I really was. Now, of course, it's not such a big deal! LOL!
However, I think I am starting to look, if not my actual age, at least older.
I'm in my 40s. While some may guess that I'm in my 30s & would be surprised to find out I just turned 44, I don't think anyone would still place me in my 20s. But I think my being a mom of 2 teenagers helps people more accurately guess my age as well - "She has a 17 year old daughter - she's probably not in her 20s!"
DH has always looked younger than he is too. I remember, right after we got married, a salesman came to our door. When DH answered the door, the salesman asked to speak to "the man of the house". LOL!