I find that if he didn't realize it immediately, he's dealing with the typical late onset effect of vaping. I think most vapes are capable of this effect, though it comes easier with some than others. I suspect it is the effect brought on by the lower boiling compounds. This effect is far different than the X-factor which is instantaneous head change. This is a late-onset effect. People who are conditioned to the immediate head change that combustion brings have a hard time making the association with late-onset effects, or so my observations would lead me to believe. They often prefer the X-factor. That being said there are also those who don't get late onset effects, and for them it appears to be X-factor or nothing.