Can you really teach someone how to love though? I'm viewing this topic through a biologist lens and not a psychologist lens. Love is a complicated, chemical process and I do think there are people where this process does not work correctly at all. In animals the closest thing to "love" would be the bonding that monogamous species take part in, I suppose. But equating that to human love is anthropomorphism. Sex for monogamous species is supposed to accelerate the bonding process and allow for them to become better parents to raise offspring.
So, how do you teach someone how to love if there's never any bonding chemicals that happen for them? Most people go through a "honeymoon phase" in their relationships but if the bonding and love processes work properly, their relationships are maintained past that phase. I also think the people shown in this thread also don't understand the importance of the communication aspect in relationships either--or maybe they are all just socially stunted in several aspects to begin with. The complete disregard for their partner's emotions in these stories is also something that amazes me.
The brain is biological, and thus follows the same rules of biology and genetics, if that helps you get my psychological viewpoint.
I believe people can learn to love, even later in life just due to neuroplasticity and flexbility of the wiring of the brain, but it does depend if they just even have that simple wiring in the first place-- sociopaths, for one, may not have this wiring. Of course, when I say "wiring", that is a complex thing, and has many underlying implications, which I will try to define below somehow.
Love at this level is very hard to define, as there is familiar love, romantic love, friendship love, and absolute love: in greek, these concepts have their own words: philo, eros, and agape (friendship, romance, and absolute love). It depends on how you look at how these three systems develop physically within the brain, as they both hit the concept of "love", but in much different ways. However, they are all representative of "bonding" in some level.
I guess the best thing we can look at are sociopaths, those with the complete inability of "empathy", or the emotional stance of understanding/bonding with people. All of these systems I have referred to simply derive from the brain's intrinsic process of bonding and understanding others, and that is what simply love is in a biological standpoint: the ability of the brain to send physical signals in order to give a sense of "bonding" and "caring" with others.
So loving yourself is simply rewiring your brain, or developing habits and behaviors, which are beneficial to how you view yourself in all of these categories: it's simply making sure you survive and thrive, and bond with yourself and what you are in essence.