There are a lot of factors but I'm pretty sure most headlights are brighter than they are regulated, but they make them too bright because that's what sells, and it's difficult to enforce a lumen limit. As others said, lights aren't aligned well. But also a lot of roads in VT, I suspect, are angled such that even properly aligned lights will end up hitting you in the face. Finally, I suspect lots of people just use auto high beams and these are imperfect.