Suicide of Lagos politician, ex-Unilag student why?

I usually do not hesitate before writing a blog post, but this time I did. In the past seven days, I have heard about two suicides. These are from people I know who were impacted by this - thankfully I personally did not know them, but this was not just blatant news. Before this, I think I knew of one suicide in my life time. Thankfully, I have never had a direct friend or family member who went that way.

Firstly was the alleged suicide committed by 56-year-old former Lagos State Peoples Democratic Party senatorial candidate and ministerial nominee, Al-Mustaim Abaniwonda. Hitherto, there were conflicting reports about how the politician died, though initial report said he committed suicide, his family has since disputed the story.
While we wait for the police report to ascertain the real cause of death, one wonders how a successful businessman will take his life?

Another bizarre story was pretty 26yr old Motunrayo Agbara's corpse discovered hanging from the ceiling of her sister’s residence on Allen Avenue, in Lagos on Monday July 18.
The story was she committed suicide because her boyfriend jilted her, but her family have dismissed it.
Late Motunrayo had an operation last year that affected her uterus (Cyst), her womb was removed, so that contributed to her depression, which she complained a lot about and even attempted to kill herself last year but was rescued. Guess she succeeded this time around. So sad!

She finished from Queens College in 2001, was a graduate of Economics, University of Lagos and an ex-employee of Access Bank. She was buried yesterday Tuesday 19th of July at Vaults and Garden Cemetery, Ikoyi. May her soul rest in peace...amen

Suicide is something I simply cannot understand. I just can't comprehend it. No matter how bad life is for you - I just can't understand why someone would do it. Don't get me wrong, I am not judging anyone - I am just saying, I don't understand the rational.
No matter how bad things are, committing suicide hurts so many more people. I hate to say this publicly, but to me, it seems like a selfish act. Of course, I cannot comprehend how bad life is for people who think about doing such acts - so me saying that, is easy for me to say and does unjust to those who suffer with these conditions (if it is a condition).
I just wonder, do sane people commit suicide?

May their souls rest in peace.