But to start with, I used to think the heart plays the game not the mind. Since mind can figure logic and what's good and what's not good. But the heart wants what it wants even if it is not good for us.

I want to stress that this is an opinion of mine. I could be wrong. But for me, logic is a tool that we can use to attempt to discern truth, or that we can use to rationalise truths that we find more comfortable than the ones staring us in the face. I also think the mind has a tendency to attempt to define what is good (in a moral sense) for us, where as the heart, simply knows what it is good even if the mind does not. I can agree that the heart may want something that it is not good for us personally, but I believe that it wants what is good for all of us. In short, from my perspective, the mind is selfish, while the heart, is selfless.

Lets say when you are in love with a drug addict who beats you - Your heart wants him no matter if he beats you after drugs. But your mind knows your lover is not good for you. See here heart is playing with you but mind is helping you.

I read this message of yours earlier and it actually got me thinking a lot. I spoke to someone who I know has been through something very much akin to what you described. I asked them if it was not the mind that was concocting reasons to stay with her abuser for fear of facing change. She said it is very possible, but couldn't be any clearer on that. What I do know from personal experience, however, is that it can be difficult to understand what the heart is telling us when we've ignored it for so long. But, the more we pay attention to it, the more accurately we are able to discern its demands.

But in case when someone loses their loved one - Your mind would keep messing with you but your heart will tell you in merciless manner that your loved one is gone and it would focus on the truth.

This is very interesting and makes me doubt my words more than the last thing you said. Because it's difficult to deny that the pain of loss is felt in the heart. But, I see not what the purpose of the pain is. It seems entirely unproductive, because they're gone. So, I shall have to think deeper about why the heart insists on making us hurt when someone is gone, and when there is nothing we can do about it. It seems to me there must be a purpose. Thanks for that. I do love having something to think about that I haven't pondered in the past deeply.