Nicotine is a strange drug in general. It's a lot like caffine in some ways, with the addiction attributes of cocain or heroine. Smoking analogs before sleeping hurts your sleep cycle, but it takes away the withdrawl issues of not having the nicotine, allowing one to fall asleep. Vaping the nicotine serves the same purpose. Problem is when you first quit your body goes through withdrawls on all the other chems inside a cig, and the nicotine in vaping takes longer to break the blood brain barrier than in analogs, so people usually end up vaping more. That leads to the caffine like effects of the nic. Doesn't help that most newbies (myself included) seem to vape more than they smoked due to the fact they can do it anywhere, and honestly they taste a lot better than traditional cigs. As many have allready suggested use a lower level at night.
Luckily V4L included a few lower nic level freebies in my order that were close enough to what I craved (Cool 8mg as opposed to WOW Nuport 24mg) in my first order so I was able to do just that.