When?
Around age 30. I had dorky uncontrollable hair as it is, and losing it so rapidly has only made it even dorkier. I also don’t like cutting it very short, as it spikes. Generally my hair has been a bastard.
Sometime in my mid 30s IIRC. At first it was only a “widow’s peak”; that runs in my family. It only started seriously a few years ago. I’m probably going to start wearing hats to keep my head warm.
I have multi-colored hair, red, dark brown, and light brown. The light brown stuff on the front all fell out in my 40s. Then the red disappeared thinning out my hair. The dark brown is still there, but slowly receding. Similar thing in my beard. The light-brown and red turned gray. I wear hats a lot, and people see my mostly gray beard are surprised the hair on top is still brown. Doesn’t bother me much because both of my brothers have lost almost all their hair.
50 years old with a full head of hair. Fortunate genetics.
Late 40’s. However, I started going gray at 18.
I’m 26 but I have a pretty high hairline that might be receding. I’m certainly going grey and might be completely grey by the time I’m 40 though!
60, no loss yet. Went grey at 39.
Around 21 years old my scalp started becomming sore all the time as if it were burned, within 2 years I lost about 75% of my hair, did not recede just got very thin.
I first noticed by balding head in my mid 20’s. I was going through security at O’Hare Airport in a relatively one of a kind shirt.
I looked at the closed circuit TV above me and my immediate thought was “who’s that bald headed guy who has the same shirt as I do?”
Started to get the receding hairline (the “fore-and-a-half head”, followed by the “five-head”, etc.) by the time I was in grad school, so that would have been age 22 or 23.
Didn’t really realize my hair had gotten considerably thinner on the top until I was on a Caribbean cruise just after my 28th birthday, and sunburned the crap out of the top of my head.
47 now. Hair is thinner still on top, but I’m not bald yet. 
I’ll be 48 in less than two weeks. Lost most of to two years ago due to the Chemo. Has since all grown back and is down past my shoulders again. Lost the bottom half of my beard from the Radiation. Still doesn’t grow back except for my goatee. Now I have a Civil War Beard. Only a touch of grey at my right temple and salt-n-pepper in my goatee.
Best cure for dorky hair is a razor. I started sporting the ‘EL Domo’ a couple of years ago, and have been lovin’ it ever since.
First year at university, so around 18. Being the first of your peer group to lose his hair is great fun.
38 or 39. i’m surprised it lasted that long
The problem with that is I’d have to maintain it every week, which I’m too lazy to be bothered with. Plus I live alone so would either be paying for it or doing a (literal) hack job on myself. Plus I think I have a funny shaped head.
Even though I have a girlfriend who could do, I prefer to do it myself. It really isn’t hard.
55, full head of hair. Slight tinge of grey just starting at temples. My beard has been grey for years (although I don’t grow it)
Not yet. Nearing 60. I can’t tell but my barber said last time I went that it is thinner. He’s happy about it because he said it was difficult to get it to sit evenly because it was too thick.
Mid 20’s, started losing some from the sides of the temples.
The use of the right conditioner, and taking care not to yank out the tangles, has helped to greatly slow down the rate of loss.