Riddle 20: Answer

I regret,
not rising.

Regret and decline are related expressions. Regret is politer
Declination is measured north and south of the celestial equator, so cannot rise.

I regret,
not receiving.

Declination is not reception. Planets that are parallel may or may not have reception with each other.

I regret,
not coming to the point.

A parallel by definition is formed by two lines that do not share a single point. They do not intersect.

The objects of my sloping attention,
Are set on rails. Do you know what I mean?

A decline is a slope. And rails are parallel to one another. I wouldn’t want to sit in a train where that wasn’t so!

They will never meet,
though they still may form a team.

Parallel lines never meet. But planets parallel to one another are indeed teamed up.

I regret……………………………
………………………………………
………………………………………
………………………………………
………………… but I’m not sorry!

No Parallel worth its declination is sorry for anything.