Intersection of a line and line at infinity in projective space I understand parallel lines in Euclidean space intersect at the line at infinity in terms of projective space. 
My question is for a single line. A single line if extended to infinity must intersect the line at infinity at some point (correct me if this wrong.). The thing that I find hard to interpret is how could it not intersect the infinity line in two points which are located in the two opposite directions of the line?
I have checked this existing question line at infinity and it didn't help.

Each line has just one point at infinity, which is approached by going in either direction along the line.  Two lines share the same point at infinity if and only if they are parallel to each other.  Two lines not parallel to each other have different points at infinity.
When one adds to the affine line a point at infinity that is approached by going in either direction, the line becomes topologically a circle.
