Question about that 500 bricks a day figure from the old union pamphlet

I was cleaning out the truck last week and found an old union pamphlet from a job in Gary, Indiana back in the 90s, and it says a good layer should hit 500 bricks a day. That number has been stuck in my head ever since because on my best day last summer I did maybe 320 on a straight wall with no cuts. So here's the debate I keep having with myself. One side says that 500 number was for a different era, bigger bricks, simpler walls, and nobody should feel bad about not hitting it now. Other side says we've all gotten soft and the old guys really did lay that much and we just make excuses. I asked my uncle who ran a crew for 20 years and he laughed and said the 500 number came from a speed contest, not a normal shift. But my foreman swears his dad did 600 on a school job in Hammond. I honestly don't know who to believe. So for the guys who've been at this a while, what's a real day's number for you, and did anyone ever actually see a guy hit 500 on a normal wall?