Be grateful for what you have and stop complaining - it bores everybody else, does you no good and doesn't solve any problems!
You become great by going small thing in a great way.
Little men with little minds and little imaginations go through life in little ruts, smugly resisting all changes which would jar their little worlds.
When we change the input into our minds, we change the output into our lives.
When you choose a habit, you also choose the end of that habit.
It might interest you to know that the 1828 Noah Webster Dictionary identifies the optimist in complimentary terms, but says nothing about the pessimist. The word 'pessimist' was not in our vocabulary at that time. It's a modern 'invention' which I believe we should 'dis-invent.'