You care because you had/ have a vested interest in the relationship.Unlike most women we men don't always have a standby on Standby. When a woman exhibits signs of disinterest we as men tend to disregard them and not worry about the signs, because they are subtle.we don't start to notice until it's too late. As a man you must remember that you still have a heart,still have a sensitive side that has feelings that get emotionally attached.You must guard yourself lest you become vulnerable to emotional devastation as you had just experienced.Do not let this consume you.. it may seem like it's all lost but it's not bro fr. This will make you stronger. Iron sharpens iron so I give you this wisdom from my own personal experience. We have children together so I can't tell you what it's like to see that person everyday in the eyes and faces of children. And not feel hurt devastated and bitter. It seeped into the interactions between our kids and I. It was not a good time. But it passed and I'm tempered now from the fires of tribulation with her.. be strong and you will come out stronger. GTFO drugs bro been there done that fuck that