Suicide is nothing more than self defense against the person who is ruining your life. Suicidal people are simply angels that want to go home.
I couldn't imagine things being so bad that I would end my life over them. There are some instances though where I could understand it. Like Obisdian said, being blind would be horrible. Other situations :
- like the girl from my school I described
- losing my arms or legs, or being paralyzed
- having a slow developing terminal illness
But some of these people that kill themselves because their girlfriend broke up with them, or they lost their job, or silly shit like that (which I understand is not really silly in their eyes), those people could have toughed it out and made something worth waking up for each day.