Somewhat like you two, I'll sometimes be going about my daily business when, out of nowhere I'll have a suicidal thought that passes through my head. Sometimes these accompany what bluebicycle calls "apathetic depression," but other times I can be in a normal mood & I seem to have an existential moment when I picture myself commiting suicide...with a plan & everything. I haven't attempted suicide in many, many years, & know my recent thoughts are just thoughts that pass like clouds in the sky & don't really disturb me too much. Strange.