I've frequently heard that it's best to be aware of the present moment but sometimes it seems a little too difficult to remember. When I do remember, I feel so alive. Life turns into a sort of "High Definition" experience.
To help me remember I wrote "Here, Now, Enjoy Life" on an index card and set it on my desktop.
I made up a simple brief mind map.
It is impossible for anyone to be happy all the time. Life can be hard. But it is a very interesting concept, even though I only remember to do it about ten percent of the time.