As a confirmed "all-things-Spanish and Spain lover", all the reasons given are valid - but, as one who lived in Hawaii for 20 years and somehow ended up in Boston - i.e., where the sun shines and there is daylight 365 days of the year (and it does rain in the Islands ;)) vs. where the sun shines about 183 days a year with an equal amount of daylight - SAD does really play a part!