bpd comes with being very self-centered. What can you expect from someone at an emotional age of 3 ?

But some of you do have dogs, a lovely animal, but one that requires a lot of attention for it's needs, the opposite of self-centered-ness. And from what i read, in at least some of us manage to treat our pets well, which sometimes can be extremely difficult. 

How does this happen ? Why doesn't our self-focus makes us unable to care for pets ? 
