Intuition, irrationality, always some explanation, maybe. Though you might not at first be able to explain love, there are chemicals which the sensation and bond can be attributed to. It's all very complicated, no doubt. Emotions are not unique to humans, but we are the only ones who can override those instincts, as far as I'm aware of, with a few exceptions, maybe, of our closest relatives in the animal kingdom, rarely. The lines become blurry for human-level sentience.
Such things as human emotions, and the ability to process them, are a part of what makes us "human", in many ways. Though we would not be able to survive if we simply put pure emotion before logic, most, if not all, people are, ultimately, emotion and sensation driven. Emotions, feelings, and sensations drive all animals to do things, on varying levels. We cannot explain emotions and sensations in their raw context. We do not know precisely the nature of pain, we only know the sensation, and that stimuli and neurotransmitters make it so.

Whilst intuition may not be understood by science yet, it is unwise to automatically dismiss it, as there may be some otherwise unseen factors which are subconsciously detected.
I admit that a hunch will make me suspicious, but then I will look for evidence that justifies such. I find caution and vigilance to be the best policies.

Logical and rational study tries to make sense of the world, and provide solutions and answers to dilemmas, whilst creating new problems and questions in the process. The ultimate goals of science and logic are to explain everything. Perhaps eventually mankind will.