Why don't women learn from each other's abuse incidents?

Just about every woman who has been with Charlie Sheen including John Travolta's current wife experienced Domestic Abuse with him. The same with OJ's women. Yet, the cycle continues. OJ's last girlfriend said she felt she couldn't "escape" him until he was sent to prison. After awhile you tend to lose empathy for women who think they can change him when no one else could.