A weird thought

I wonder if depressed people were chosen to be depressed,
and others were just meant to be happy,
or maybe you just develop it from some tragic event,

all of my friends say I have it good,
but I think to myself,
that actually they are the ones that do,

They aren't depressed,
they don't feel like dying,
they are always happy,

they don't cry themselves to sleep,
they don't thrive for the blade,

I try to be happy,
it lasts for awhile,
but something goes wrong,

and I am back where I started