I have been mixing my own juices for a while. And I was at 0 nic but i do go back to nic from time to time and it seems to have a bite that 0nic does not have. This is also something i have noticed with store bought juices. I tend to vape 0nic at lower wattage. But with any nic at lower wattages seems to bite so much harder at lower watts(90 watts) i have to crank it up to 200 watts to enjoy the vape. Is this normal? Did the nic lose its freshness or something? Your thoughts?