At what point does forgiveness become foolishness?

When abuse of any kind is involved. The first act of forgiveness in an abusive situation was already a huge mistake.

it becomes foolish when you forgive and forget. NEVER EVER FORGET!!!!!!!!!!!

When you see that the person takes it for granted and doesn't learn but instead, does what they want and put your forgiveness as leverage for their success.

When the other person doesn't deserve forgiving because they won't change their behaviour.

Not always, but sometimes it does, for sure.

forgiveness is never foolish, people are though. Forgiveness is divine