Why do females hold grudges?

I'm not a perfect person by a long shot. I realize this, and I don't expect anyone I talk to.....whether it be on a friendship level, or deeper, to be perfect, either. I've been done wrong in a lot of ways during my lifetime, but I am a very forgiving person, and am willing to give second, sometimes even third chances. But as of late, I have noticed that the females of this day and age are not very forgiving at all. A lot of females go by the "one strike, you're out" type deal. It's almost as if females nowadays demand perfection and flawlessness out of the males that they deal with. So females, I ask you, why is it that some of you find it so hard to give second chances, or even worse, hold grudges and not even be willing to hold a conversation with a person after only one mistake?

It's not just the females that hold grudges, bruh...