Why some people in life are happy and other people are miserable? Is it all about our decisions?

Happiness is just inside you. You dont need any particular reason to be happy. 

The solution: when your heart dies you will enjoy life

The cause of happiness and unhappiness content are present in all life. Perhaps it is the matter of balance or level that aggravates or affects life. Untimely acts of any kind, immature or premature decisions based on certain impulse, etc results in one of these factors but not evitable. Why it is not as it is a truth or phenomenon similiar to day and night or black and white. Actions lead by enough thoughts, calculated ground work, wise advises, past experiences, etc are few that really helps to reduce the impact of unhappiness factor. Again, the happiest are those successful in managing unhappiness content in their life or successful to overcome with incredible optimism, positive thinking and recommended dose of spirituality.

Yes it always our decisions ,,,

Thanks for invitation