While many people will be out wining and dining their loved ones tonight, or even popping the question, a small but substantial minority could be finding the whole event a serious drag.
That's because about ten percent of Spaniards suffer from alexithymia, a condition which makes feeling and recognizing emotions more difficult than it is for other people, according to the Spanish Neurological Society (SEN).
"This is a personality trait and an abnormality but it´s not clear whether it's a disorder," SEN professor Pablo Duque told ABC newspaper.
"Alexithymia is typical in patients who have suffered neurological illness and neurological or psychiatric illnesses, but the most common form is emotional disorders like depressive syndromes or mood swings," Duque added.
People with alexithymia don't lack emotions but they do need to develop them. Their inability to express their feelings also means that they sometimes resort to gestures rather than words as they try and show how they feel.