Relative to the age of the universe, as best we can guess it, our earthly human lives are but a brief moment in time.  We can speculate what happens after this life but it is not definitively known.

During our short lives, we have the opportunity to experience joy and pleasure.   Of course, we can also experience pain and unhappiness and every range of emotion in-between.

Control

What we experience is not totally in our control.  Events, the activities and interventions of others and perhaps extra-sensory factors are not always fully in our control.

How we react to the things going on around us, what we feel can be controlled by us consciously albeit sometimes requiring quite a bit of effort.

Our sub-conscious can take over sometimes without us even realizing it.  Hence negative emotions and feelings can arise within us before we are able to take control and quench them.

Blind Happiness and Joy

I firmly believe how I feel at any point in time is up to me and fully my choice however reality does intrude and I do find this is not always the case.

Or perhaps it is and I choose (even to a largely sub-conscious extent) to worry, be fearful, sad and unhappy on occassion.   Given the negative context of these feelings though, I wonder why I would ever choose this route (but maybe that is part of life).

I wonder if joy, pleasure, and happiness can be continual and uninterrupted if I choose to make it so.  My experience seems to lead to the conclusion this is not the case.

That being said, taking control of how I feel and channeling my thoughts and behavior to the positive is always worth the effort although sometimes it is not always doable.