While I was reading How not to be wrong by Jordan Ellenberg, at one point came across this, "a line is one kind of curve, but not the only kind and lines enjoy all kinds of special properties that curves in general may not." Can someone explain this, please? Thanks in advance.
P.s: What are those special properties that he is talking about?
Two lines (in the plane) always intersect or otherwise are disjoint, while curves can intersect in any number of points, to name but one special property. Lines are homogeneous (all points look the same) etc.