my tb gelding was similar, though he was 18. when the farrier would come out to the farm, he'd honk his horn to let Blue (tb) know he was there. Blue would haul himself as fast as he could to the gate, stand there until the farrier got in (never ever ever had to tie him up), and then pick up his left front foot. the farrier did his work, and Blue would walk away about 100 yards, turn and walk back. if he was happy with his feet, he'd turn back around and take off running (like a kid with new shoes). If he wasn't happy with the way a foot felt, he'd stand back in his spot and take the weight off of that particular foot. The farrier would usually do Blue's feet for half price because the horse was so well mannered about his pedicures!
We don't know how he managed to get into this habit, but he'd never do it for another farrier. We bought him as a freshly retired racer and he was the one I learned to ride on. Came with a load of oddities - didn't like normal treats (apples, carrots, sugar cubes, etc) but preferred Oreo cookies, or cookies N cream ice cream lol.
He's a great horse!