If all happiness is relative then we could divide experience into 2 parts:
The background and You.
Also, another factor is where you plot yourself on the background.
1. Lets say this is the background you see:
-ve ———————|———————- +ve
It is basically all the possibilities appearing in your imagination.
Now this background itself shifts with your changing moods and perceptions even during a single day.
It may not shift around much though most of the time.
But it can dramatically move around, when your doing deep inquiry and elevating consciousness into the nature of everything.
2. The next factor is where you plot yourself on this imagination spectrum that appears in awareness.
Case 1: If you consider yourself unfortunate and cursed
Case 2: If you consider yourself blessed and fortunate
This is a heavy simplification, but could be an interesting train of thought to pursue.