Being a very rainy day today, reminded me of a speech by Rabbi Moshe Weinberger of Aish Kodesh. He explained the connection between the physical and the spiritual. Ever wonder why people get sleepy when it's raining and the sky is grey? Certainly you could find a scientific reason for it but Rabbi Weinberger's explanation was fascinating and perhaps a bit kabbalistic in nature. When people were farmers (yes people actually grew their own food) their whole economy was based around the rain and it's ability to produce ones produce(I know I used the same word twice)! The the rain and grey clouds therefore represented that G-d was taking care of them and serenity would fall over them ( a comfort of sorts) . Hence the sleepy feeling of calm and knowing things are being handled by the one of above would occur.