Hi and welcome to ECF. You are right that the nic levels can be confusing. Part of the reason for that is that nic is absorbed differently when vaping versus smoking. From what I have learned since vaping is that recommended levels aren't going to work for everyone. I know one person who smoked 2 packs a day and 24mg worked great for him. I smoked about 25 a day and 18mg worked great for me, though I have since dropped to 12mg. A co-worker of mine also smoked about 1 1/2 packs per day and 18mg was too much for her, so she dropped to 12mg and it is working great for her.
I hope you find what works for you and that vaping continues to be a sufficient substitute for analogs. Thanks for sharing your experience. I've learned that we are all in this thing together and that is why I like the friendly, supportive, knowledgeable and non-judgmental community here.
Keep the vape and namaste.
Not sure with folks who are occasional smokers. It is good to remember that it takes nic a bit longer to "hit" when vaping compared to smoking, so not quite the almost instant nic hit like there is from smoking. That may affect how your body (and brain) react to nic while vaping, because it does not hit as quickly.
If 18mg is working for you right now, stick with it for a while. You can always drop nic levels a bit later down the vaping path. One thing that folks here have taught me is that getting off of analogs (if that is your goal) is a marathon, not a sprint. So whatever it takes to stay off analogs for today is the right choice for you.