Reality sometimes holds you by the scruff of your neck, and removes the scales from your eyes. Primarily, human beings are meant to share some of their emotions so that they are able to fulfill their collective aspirations. It is no rigorous exercise, but is based on something as basic as trust in a fellow creature. As maturity further obscures the definition of love, reality begins to lose the thin film of haziness that shrouded it.
It is when concepts get clearer that life gets more difficult.