Did we evolve to have emotions as time and energy saving heuristics for more expensive cognition?
Our brains were like, "Damn, that's too much to think about, so I'll just decide based on how it makes me feel."

Theories of emotion have been arguing for decades about the role, sequence, and relationships of physiological, cognitive, and emotional reactions to environmental stimuli (as well the role of learning and experience in shaping subjective interpretations.)