How can I feel happy even if there is no any reason of happiness in life?

One of the best ways to generate happiness with no significant reason is simply by becoming aware of:

1. All the wonderful blessings you are enriched with, which includes your eyes that enable you to read this apart from many other parts of your body that allow you to lead a normal life. This TED talk will make more sense to what I am trying to say. 
2. All the resources that you have an easy access to. The very thought that roughly 3.1 million children die each year due to malnutrition (which makes up approximately 8494 children everyday according to the data given by WFP), it will be difficult for you to not appreciate the most simplest of resources that you have an easy access to by which I mean "food" 
3. All the lovely people (even if they be one or two). A study describes a condition called as Emotional Deprivation Disorder, a syndrome which results from a lack of authentic affirmation and emotional strengthening in one's life. A person may have been criticized, ignored, neglected, abused, or emotionally rejected by primary caregivers early in life, resulting in that individual’s stunted emotional growth. If you have even a few people in your life with whom you can open up and share whatever it is that you wish to, then you indeed have a good reason to celebrate life without the need to have any significant event like becoming the CEO of the company you work for