You put it so well Sue...how to explain the unexplainable. I lost a son to suicide and he left an eight year old son of his own behind. That's one reason I was so angry at him....I understand that you don't "get it"...it's a common reaction I get from people.
Why on earth would someone "choose" death when there's always the hope that things will change, improve.
I don't believe he "thought" about it...he just acted impusively but of course I'll never know for sure.
I'm so sorry for your losses.