Is it normal for some flat billed hats to have extra forehead space?

Got my bf an awesome motocross flat billed hat since he lost his old one. Problem is, I tried it on and it has wayyy too much forehead space. Idk how it will fit him but i don't think any better. What is the purpose of this? To even out the appearance of receding foreheads or what?? Do you have a hat like this and actually wear it???