These people are not monsters, these posts of: "My girlfriend/boyfriend did all these horrible things
" therefore he/she is a evil sociopath is just plain stupid, how do you have any idea what is going though their head. A sociopath would not do these things maliciously, with the exception that it was entertaining, they would toss you aside because you no longer pleased them (entertainment/sex/lifestyle) and then forget (not literally) about you. Quit the mind reading, it only enhances the misunderstanding, perhaps it may have even been one of the causes of the breakup instead.
Interested is a very loaded term here, whatever draws a sociopath to something is their interest, be it for financial gain, sex, or just keeping the boredom at bay. This is their guiding star, doesn't mean you can't gain something from them at the same time or simply co-exist with them. Simply put, realize that even though you are a screwdriver, they won't necessarily throw you, instead of placing you in the toolbox when done, he/she might instead put you on the velvet cushion as the favorite tool.
Please beware of diagnosing yourself or others who have hurt you. Just because someone has lied to you, tried to take your children from you, or done other wrongs to you does not mean that they have a mental illness. Similarly, just because you have done these things does not mean you have a condition. People by nature are hurtful and selfish; does that mean we should diagnose the entire world population as sociopathic? Such a diagnosis, if false, could ruin a person's life, as well as the lives of the people around him.
Does this mean everyone who commits murder is a psychopath (enjoyed it)?
At the same time, if you do come into contact with someone with the above qualities, sociopath or not, you should probably steer clear of them!