[brigandish]

Perhaps the causality is in both directions. Something I learned from doing Tibetan lamrim meditation - where you use memories and imagined scenarios to produce specific emotions to arise - is that you can start with something quite artificial or forced but this will lead to something genuine later down the line via practice. For example, if I think about all the things my mother did for me through my life, even before it, dreaming about me before she knew me, wishing the best for me, keeping me safe and trying hard to get me the best education, the best upbringing she could and so on… that can start off (and probably did in my case as a selfish ingrate) as a thought without the associated feeling of gratitude but I can tell you that writing that right now brought tears to my eyes as gratitude arose immediately.

In the same way, perhaps it's the case that if you remember more about more people then you will care more about more people? Certainly, making the effort to remember would suggest you care to begin with and wish for that to grow.