Once upon a time

... there lived a remora who dreamed of true love. He was a thoughtful type, and read all the literary papers. He had long been suckered to a blue whale, who was very clever but didn't tend to the remora's brand of ocean-gazing. The remora spent a lot of time worrying about the difference between commensalism and mutualism. That was partly because it was a real worry for him, and partly because worrying about that sort of distinction was part of what did it for him in life generally. If he was bored, he'd look for a distinction to draw. Or one to collapse, if it seemed too obvious that there was one.

One day, he asked the whale what she thought. I don't know what you mean, she said. Well, said the remora, do you think that I'm basically just hitching a ride, or are you getting something important out of this?

This what? said the whale.

Me! said the remora.

The whale turned her eye to him bemusedly. But you'll always be there, she said.

Moral:

Stop up the access and passage to remoras,
That no compunctious visitings of nature
Shake my fell purpose, nor keep peace between
The effect and it!