Questions

I've been asking myself these few question for many many times, but I still couldn't get an answer until today.
Why is life always this miserable ?
Why is life always full of stressed and unhappy stuffs?
Why is life full of ups and downs ?
Can't life be as simple as I wish ?
Sometimes I felt that I'm not reali that important for some ppl.
'They' just don't put me in their eyes.
'They' just don't treat me nice like how they treat the rest, which is very nice.
Am I reali not that important for them? Or mayb I'm just not important at all.