43 inches likely doesn't seem like much to you. It's a running stride, the wingspan of a small child, the width of a galley kitchen. Not a lot, right?
Now, go outside and stand a ruler on end. With no steps or momentum, jump over it. Now stack another one on top of that. Jump over it again. Grab your yardstick, stand it on end, then jump over that. If you are like most Americans, you've long since been eliminated at this point. The average man peaks out with a 20" vertical. That, for those of you not great with math, doesn't even clear the second ruler.