Here's a little lesson for you on psychology.  

Emotions and self reports are notoriously susceptible to all sorts of "atmospherics" (there's like 50 variables that can influence even the simplest study of human behavior). 

The real thinkers in psychology..the ones with math backgrounds...built a field called "psychophysics" (Stevens, Fechner, Weber, and more modern ones such as Walter Gogle, etc.), & they showed with great rigor just how fickle and unreliable and easy it is to severely bias subjective measures.  They developed fairly reproducible mathematical functions between stimuli and responses. 

But this was with very simple set of stimuli..such as weights, and lights and so forth.

And they also showed how simply changing the order, or the location in a series of the most sizable stimuli, could change all successive self-reports.  

And can you imagine how unreliable self reports are of things like happiness, preferences, "belongingness", and other goofy modern variables are?