Do it a hundred times.

I bet there’s not much difference in the way that an amateur and a professional lay one brick. But I bet there’s a big difference in the way they lay a hundred bricks, or a thousand bricks. 

I remember debating with a friend whether or not a $2 Australian coin was thicker than a $1 Australian coin. I thought it was, he thought it wasn’t. We had the coins in front of us. It was hard to tell. But when we stacked four $2 coins next to four $1 coins, it was very clear—the stack of $2 coins was taller. 

If you want to know if you’re holding your head too far in front of yourself while you’re running, you might not find out after a 20 minute jog. But you’ll find out after a marathon.