Crazy type a loving he wants to give

So I've been experiencing this specific problem alot over the years and after stopping to observe I've noticed that some of my friends are having this very same problem as well.  Now it's not like this is an every day or everyweek occurance but when it happens more than thrice  it's a cause for concern.  Now, why must people behave the way they do when  they are shunned  and why is it almost acceptable for them to carry on with their antics...  It's  my belief that persons bad behaviour is continued when no one calls them out on thier Bs... 

Now the  observation I've had is that men are picking up the habit of becoming and acting like complete psychopaths when u shun them. I know this one lady who knew this gentleman, a sweet quiet soul who would make the perfect husband  for a woman who requires a life as dull as possible  with little to no upward mobility but a life with a man who absolutely adores her...  Now after much pleading that the gentleman step his game up and sort out his life the lady had to pull up root and move on...  That is when  the dragon beast reared it's ugly head: the man now aptly renamed the ole Fawt started calling her place of work, Stalking her home ', harrasing her friends and relatives and even threatened to expose intimate details of their relationship to the online community.  Now even if the lady wanted to give this man a second  chance in her life all  prospects of this were dashed when the old Fawt started to act up.

My question is this : what goes on in a man's head that would cause him to want to behave like this?  Why would  he believe that actions such as those could ever win him back his significant other.  As a  sensible individual living in today's world I believe that it would be obvious to any man that the way to  win back a womans affections would be to work at whatever short comings one might have and become the sort of person that the woman would not dear live or love  without. A man who wants his prized possession back would not dear do anything to upset her or make her unhappy... that is what we think.  It's almost as though they have no regard for themselves or the women they proposed to love when the  switch of single life is turned on.

Another instance of men going crazy that I've witnessed is the other day when a friend of mine was going through a fairly amicable breakup she and the gentleman were still friends and I genuinely applauded the love being shown...  The gentleman however had other plans he wanted the lady back n became crazed one day after she rejected his intimate advances.  The  lady wanted the gentleman back in her life but after the ole Fawt carry on and acted quite crazed she was sure that that was the end of the love/relationship road for them.

When love is lost it is a sad, miserable time and the parties involved will probably hurt like nothing else they have ever experienced but why degrade the integrity of the love by acting foolishly, jealously or quite frankly psychopathically.  One never knows what is destined to happen and overreaction and disrespect might ruin something that might have eventually rekindled to be something unbreakable...

Love hard.. Love long..  Love good