But that's where the error lies. When we taste sugar we are told its "sweet". We are told vinegar is "sour". It's a learned response. It's doesn't mean we all experience it the same way.
Some people hate sugar and love vinegar. Women have a particular preference for chocolate which seems to be more than what it does for men. Others seem to really like the experience of alcohol while other hate it, etc.
Taste—in fact all experience—can be reduced to to three categories: pleasant, unpleasant, neutral. Depending how we experience something will determine not only our immediate response to it but also whether we are likely to seek to repeat it, avoid it or never think about it.
Approach-avoidance behavior says a lot about who we are and how we are put together, as well as what our present state is.
Concepts such as love, justice, truth, divine, eternal, etc. are not absolute values. They cannot be verbalized, described or visually represented. They are abstractions.
Sometimes our "common experience" is cultural. We are conditioned to respond within the confines of our cultures. For example grief, or happiness are often culturally defined responses.
As for love being something we experience in common, let's not forget that a sadist and a masochist make a "perfect" couple, yet we know they experience their love hardly the same way. :)
It can be reduced even further. All the way down to biochemical reactions.
Still there is a qualitative difference between you and a paramecium or a stalk of corn. Reductionism is useful, but inaccurate when taken as all truth; because it reduces truth as well.