Dog Days Are Over; What Does it Mean?

Since the weather outside has been frightfully cold and dreary, I thought this may help warm you up :)

What does "dog days" mean?
The "dog days" of July and August, generally the hottest of the year, coincide with the appearance of the constellation Sirius, the Dog Star, in the same part of the sky as the sun. The Romans believed Sirius added to the heat of the sun, causing the temperature extreme, and gave this part of the year its name--in Latin, of course. So when someone says, "dog days" they usually mean the 'best days of their life'. See next page for song meaning.

Florence and the Machine's- "Dog Days Are Over" Meaning
The band 'Florence and the Machine' have a song "Dog Days Are Over" and many question the meaning of its lyrics. Listen to the song and see the video on youtube here . Get a free download of the song on beemp3.com here . Or Buy the Florence and the Machine Lungs CD here .
As for the meaning of the song lyrics, I found many explanations, but these interpretations seemed best-they seem most likely, and fit well with the probable meaning.
1. "It's probably a reference to someone who feels that the best part of their life is behind them, and who is trying to remember that you have to move forward to live (there is no sense in looking back with regret). The song is worth comparing with other moving on songs: the Rolling Stones 'Wild Horses', Van Morrison 'It's all over now Baby Blue', and even the painting Gombauld is working on in Aldous Huxley's novel 'Crome Yellow'. (Florence and the Machine has quite a few references that look like they come out of Aldous Huxley novels:- especially Brave New World)."
Here's another meaning,
2. "Perhaps the song's meaning is based around this person having very bad days, but they are over. It also mentions that the horses are coming, which may refer to the devil, as he rode on horseback. So this may mean that the bad days will return. It also says: " Run fast for your mother run fast for your father ". Basically, leave your loved ones behind as the devil is coming for you. The song also mentions: " Happiness, hit her like a train on a track; coming towards her, stuck still no turning back ". This could be a reference to this person being very low and being accustomed to tragedies. This girl is struck by joy, and as a result, is paralysed by it. This paralysing happiness will kill her - 'the train will kill her' . " Happiness hit her like a bullet in the back" . This structure is mentioned twice in the lyrics. To me, it means that Ms. Welch wanted it to be known.
I think that the meaning is ' To every high, there is a low. And to every down there is an up ' . Life moves in cyclic patterns. Prepare for the worst when you're joyous, but know that another happy time will arrive when you're down. The song sounds very cheery on the ear, so just let the music tell you if it's portraying a good or bad story. Pull out your own meaning from it. Your own interpretation is what matters.

Resources:
Listen to the song and see the video on youtube here .
Get a free download of the song on beemp3.com here .
Buy the Florence and the Machine Lungs CD here
wiki answers; http://wiki.answers.com/Q/What_is_the_meaning_of_song_%5C%27Dog_days_are_over%5C%27_by_Florence_and_the_machine&diff=22596822&oldid=22578407
answers.yahoo.com;
http://answers.yahoo.com/question/index?qid=20110104064626AAZJRRr
wiki answers; more; http://wiki.answers.com/Q/What_is_the_meaning_of_song_dog_days_are_over_by_Florence_and_the_machine