according to the theory of "eternal return", where one is fixed to repeat their own life over and over again infinitely, the people who populate your lives each time are split into two categories:
constants are those that
will ALWAYS be there with each cycle (family, parents, siblings,
children, the individuals you had those
children with)
variables are those that change with each cycle, that are not always present around you each time (friends, co-workers)
your life is full of constants and variables. the
father of your child is a constant and the
woman he cheated on you with is a variable.