I'm the type of girl that likes her hair to look nice. I don't spend years styling it or anything; I basically let it air dry and go from there but I like to take good care of It and make it look soft and shiny, good smelling, and healthy looking lol.
I get compliments on my hair quite a bit from my friends that are girls and I'm curious if guys notice a girls hair. My hair is long and dark brown and slightly wavy. It's always really soft but it can be frizzy occasionally :)
Yes, we notice it. Most guys like long hair, and we can tell if it looks nice.
Now, if you changed the style slightly since last time, or had 1" trimmed, we probably won't notice those things. We might not even notice right away if your hair is 2 shades lighter a lot of the time; we might notice something changed, but not necessarily what it is. We just don't keep track of those types of details normally.
So again, we notice the "big picture" but not the fine details.