Child, child, child.
What do you mean "be happy"? What do you mean "appreciate and be grateful for what you have"? What do you mean "be positive and look at the people unluckier than you"? Theoretical! You with your little mind, how can you ever understand suffering? Life must be covered in pink for you, or you might simply colour your lens with pink. I know, I know you're going to say that I don't understand, that you have troubles and problems like everybody else and you just deliberately choose to be positive because that's the only way to be, that I don't realise positivity might not necessarily change the situation but at least can make me feel better and less stressed.
"Be happy"? "Be grateful"? What do you know, do you ever question yourself before initiating this lecture, this pointless, shallow lecture, at all? Life isn't about existing and eating and drinking and sleeping. Life's much more. And when you don't understand, when you have different views of life, different needs, different dreams, different desires, when you are in a different circumstance and simply can't put yourself in someone else's shoes, what, after all, is the point of your so-called advice?
What is there to be grateful for? What is there to be happy about? If for you life is limited in mere existence, if for you life is limited in eating and sleeping, if for you it's enough to have health and food and shelter, if for you people should live in life without dreams, without purposes, without yearning for something high, something great, I refuse to waste time speaking to you.
Besides, let me tell you another thing, dear. There are 2 kinds of suffering, suffering for oneself, and suffering for others- the latter can also be divided into 2 subcategories, suffering for someone close to you, and suffering for other people. And that's the 1 thing you don't understand. One can easily overcome or face or forget suffering for oneself, but the other type, the other type is different. Imagine, you suffer because another person suffers, the more that person suffers the greater is your suffering. And most of all, you can't really do anything about it, you can't really change it. Both that person and you get stuck, desperately and hopelessly. And here you are, smiling and lecturing about positivity and optimism and gratitude, have you experienced it- this kind of suffering? It's the suffering for someone other than oneself that torments and destroys one more than anything, sometimes even more than a lost love.
But perhaps you never grasp it, anyway.