I got mine around the same time as you did. The only brush I bought whose bristles felt like they were synthetic was the Damen Wurzelkardatsche “rice root” brush. The horse hair brushes felt like horse hair to my fingers.
I did notice that the rice root bristles felt synthetic to my fingertips, they were just too smooth and slippery to feel like a root (I have uprooted many weeds in my paddocks, no rice roots but in general none of the roots I felt were particularly smooth.)
When I lived in Chile 60 years or so ago my parents took us to the pottery market in Chillan. Pottery was not the only specialty down there, people would also make small figurines/pattern pieces out of horse hair from horse’s tails and manes. These were quite stiff and did not collapse, so not all horse hair is soft and silky. This hair came from Chilean horses, criollos or crosses, and these horses tended to have rather bushy manes and tails instead of the thinner, silkier manes of Arabians and TBs. This was why I was not surprised by the stiffness of the Haas horsehair brushes as I had run into equally stiff horsehair used for stuff down in Chile (which as far as I know did not have a plastic industry back then.)
But I did not fall down and worship the Haas brushes because of what they are made of, I fell down and worshipped them because the two horses with the most sensitive skin at my rather large lesson stable have not threatened mayhem when we groom them with the “horsehair” Haas brushes, unlike regular brushes with synthetic bristles which they do not like at all and they make good and sure that we know that they do not like them (sidling away, dirty looks, little threat movements that are feet away from connecting, and a total refusal to relax while being groomed.)
And to have high quality brushes that are washable and variable in their types for different coat lengths, etc. I haven’t really spent money on brushes in 20 years so I am pretty ecstatic.
