here's a theory.. it's about people remembering things that are
out of the ordinary, and forgetting or being desensitised to what
happens all the time...
the man who is good to the lady, his actions "desensitise" her to
his goodness.. in a way, she takes his goodness for granted and
expects that.. the baseline is set.. when he screws up just once,
that one time he screws up will be remembered..
she will keep harping on it, thinking about that one incident,
letting her imagination get the better of her.. until one day she
decides that he doesn't love her anymore because that one incident
is all she thinks about... so she cries bitterly and leaves
him...
the man who is consistently bad to the lady, and his actions
"desensitise" her and sets this crappy baseline... he does one
thing good for her and it sticks out, she remembers that one thing
and comes to a conclusion that he loves her.. and sticks by him no
matter...
it works the other way too.. with a lady who is good and being left
by the guy.. and the bad lady whose guy stays with her..