It isn't necessarily a deliberate, conscious intent. However:

I know that Mountain Dew contains caffeine and that caffeine will make me alert. However, I also know that I hate Mountain Dew.

vs.

It's part of that set of things that doesn't go away no matter what you say or think about them. Women will still be alluring, food will still be delicious, and Michaelangelo's David will still be beautiful, no matter how well you describe these phenomenon.

Surely you see the difference?