The Ex-Effect...revised

I guess it's called the ex-effect. Seeing someone that you once had history with create history with someone new can make one quite territorial. I never understood it. What about an ex-effect with someone who doesn't have someone new... but you do? what would that be called.....the ex-back effect? or the selfish ex-effect? That clearly shows how much people do not know what they want in life. Romantic relationships are generally very confusing, which is why they generally fail for most people. Here is the real question. Is it out of sight, out of mind whenever one has a significant other but is still emotionally invested in their ex? Or, is it a situation of not knowing what you want.....I truly believe it's both. You know who you want, but you can't have who you want every day of the hour, which causes the selfish ex-effect or out of sight, out of mind. But who suffers the most in this; the ex, or the significant other? Like I said in an earlier blog, the people who suffer the most in relationships are the ones that are dealing with those who don't know what they want... All of this is just a bunch of unanswered questions that will be solved once all figured out...