There are two lines.
If they are parallel, they have many things in common but will never meet.
Sadly, all other pairs would still meet just once and then go their own ways for infinity.
One solution to this problem is making one line bend at an angle to make it continue in the same trajectory as the other line.
In life, there are moments when you must bend your line. Those who do not know how to bend will tread alone, ad infinitum.