Consider a teenage girl who is contemplating motherhood.  Prior to her
becoming pregnant, it seems that she might truly judge that it would be
a bad thing on balance to have a child at this stage in her life.  After
giving birth as a teenager, however, she might also truly judge that it
is not a bad thing on balance that her child exists.  These attitudes
have commonly been thought to be in tension with each other.  I argue,
however, that when correctly interpreted in deliberative terms, as
judgments about the agent’s reasons, the apparent conflict disappears.
Giving birth changes the girl’s situation, in ways that give rise to
corresponding changes in her reasons for action and for various
emotional responses.

A consequence of this analysis, however, is that there may be mistakes
or errors in deliberation that the agent is unable to regret having
made.  The teenage mother ought not to having conceived and given birth
to a child at that stage in her life; and yet, as a mother, she can
hardly regret having made the wrong decision in this particular matter.
  This raises large questions about the relation between justification
and regret.  Williams argues in “Moral Luck” that our decisions can be
justified or “unjustified” retroactively through intervening
circumstances that make regret either impossible or unavoidable.  I
challenge Williams’ assumption that justification and regret are
necessarily connected in this way, and show that the things that drive a
wedge between justification and regret need not have anything to do with
epistemic luck.