Oppositions often show what is coming to us from others. And what is coming to us from others, is often related to shadow dynamics/complexes within, fears of that happening/being brought to self, and/or karma from other lives and selves being reflected back to us.
If we were manipulative and selfish in another life or lives (and this is usually not us as a Soul directly, but often another Soul that is from the same larger, Spirit self that created both of these souls), then we might choose a lifetime this time around wherein we get involved in with highly manipulative, selfish, etc people to our own pain/detriment.
Self meeting self. It is the law, and the deeper, innate urge of a Soul that is a child of a Spirit that is the child of a Creator/Source of pure Love.
Though, it is often during our life reviews post death of the body, wherein we come before a council of Elders (fully Source and Love attuned individuals), that we get the courage, impetus, and motivation to take on those karmic reflection patterns. Many Souls, left to their own devices, might not choose to do it, but like children, sometimes they need to be prodded by an adult, "hey, you should do the right thing. Help yourself grow up."
And one of the ways they do this, is by temporarily expanding our consciousness to a more Universal and Love oriented one, wherein we FEEL/KNOW the effects of every choice we ever made in relation to others, and we experience it from their viewpoint, thoughts, feelings. Meanwhile, while they are boosting our consciousness, they only feel love, concern, and care for us, even as they point out the patterns we need to work on.
Needless to say, the life review process is not an easy one to go through and most don't really enjoy it all that much, though older Souls will appreciate it in hindsight.