I'll drink 120 proof whisky neat and enjoy it all day, but there's something about Eggnog and every other creamy/fatty cocktail that brings forward a harsh, rub

I'll drink 120 proof whisky neat and enjoy it all day, but there's something about Eggnog and every other creamy/fatty cocktail that brings forward a harsh, rubbing alcohol-like sting that I can't stand. I'd love to know how exactly that works but haven't found any answers yet. The one I'm really trying to figure out is an experiment with soaking apple pieces in bourbon for apple pies. The result is a lovely slightly tart apple whisky that has a boozy harshness that's tamed by a bit of honey.