The seven heads that all need to eat. And as soon as you are focussed on satisfying one, the others all need attention too. When you satisfy one and turn to the other one, the first one is hungry again and needs your attention again.
The heads are the chakras. They all need to be fed with more energy all the time. And you can't just focus on one, you need to take care of all of them. You can't just fill one up and move to the next one, because they all need a continuous flow all the time.