Things can change too. I started flying helicopters at age 50, and got my CPL two years later. At the time I asked someone working on the North Sea if I was likely to get a job there at my age, and she said they were desperate for pilots and it should be fine!!! But 9/11 came along and things changed again. So I got an FI rating (age 54), instructed part time for a while, then instructed fulltime for long enough to get sick of it but to find other work, so now I'm back to parttime instructing - which I love.
In all that time I don't think I ever got asked my age, except when I was a PPL. But then, as a woman, I think back then was the only time I encountered sexism too...proves something, don't know what.
As for harder to learn things etc...well, depends what you were like in the first place, doesn't it. What level are we supposed to be deteriorating from? If your intelligence and coordination levels were pretty high, why worry.