people

Those who look happy have unspeakable sufferings; Those who smile a lot have silent tears; Those who flaunt his life may not as what he said. Do not despise yourself！Do not care about what others think of you！ Follow your heart. Happiness is like water, only the one who drinks it know whether it is hot or cold. Your happiness is in your mind not others.

'Those who flaunt his life may not as what he said'

       Those who flaunt their life may not be as they seem/appear

'Happiness is like water, only the one who drinks it know whether it is hot or cold.'

       Happiness is like water: only the one who drinks it knows whether it is hot or cold.

'Your happiness is in your mind not others.'

       Your happiness is in your mind, not others'.  [punctuation]

people

Those who look happy have unspeakable sufferings; Those who smile a lot have silent tears; Those who flaunt his life their lives may not as what he said. (this is a bit unclear. You mean "may not really be as nice as they say," right?) Do not despise yourself！Do not care about what others think of you！ Follow your heart. Happiness is like water, only the one who drinks it knows whether it is hot or cold. Your happiness is in your mind, not others.

This entry is a lovely piece of writing, and a wonderful message :)

Those who look happy may also have unspeakable sufferings;  

Those who wear a broad smile may have silent tears too;

and those who show off their happy life may not be that superficially perfect.

So, neither despise yourself nor care about what others think of you, you just need to follow your heart.

Happiness seems to drink water, and you yourself knows whether it is hot or cold, and your happiness lies in your mind instead of others'.

Those who look happy may also have unspeakable sufferings;
Those who wear a broad smile have silent tears too;
and those who show off his happy life may not be that superficial perfect.
Do not despise yourself！Do not care about what others think of you！ Follow your heart.
Happiness seems to drink water, and you yourself knows whether it is hot or cold. Your happiness lies in your mind not in others'.