Alicornutopia

The hair darkening as you get older is a thing humans do, too. I was pale blonde when I was a little kid and now I'm a brunette.

Seconding Maggie -- everyone in my family seems to be born very-pale-blonde and end up very-dark-brunette by the time they're school-age.

I had black hair as a baby, nearly blonde as a kid and now I have medium brown hair. :|

Yeah my brother's hair started out pale blond and is now sort of light brown/very dirty blond.

I had a lovely shade of golden blonde as a kid which started to darken at around middle school age. Now my hair is chestnut brown.

1) How old do amentans look like at 20 when compared to humans?
2) Is it possible for there to be a country that doesn't honor other nations' matrilineal/patrilineal caste determination on mixed-caste immigrants and makes them change caste?

“Keep your nose on”?

Amentans look like human 40 at Amentan 20 and like human 75-80 at Amentan 40.

There are not those.

It doesn't make less objective sense than "hold your horses".

“Hold your horses”, I always assumed, made sense back when people used horses. I don’t think decades-old Amentans’ noses tended to fall off due to excitement.

All right, it makes as much objective sense as "knock your socks off".