I think F5, Had it right.
The truck sits high, and the beams are designed to shoot straight out. The High beams shoot out Higher than the regular beams so the up front ground illumination is lost, and the appearance is changed that much more, if like me, you drive with your fogs on.

Although, I have driven on super dark roads, and haven't really found the need to use the high beams. The regular beam goes out plenty far and the fogs illuminate the immediate ground in front of the truck.

And yes, I too have had folks flash me thinking my brights were on. What a suprise they get when I flash mine. They thought that the regular beam was bright.
WOW! Now they can look into the sun, until I pass.