Hey Alan, you’re not the first one remarking about numbness after sleeping on the lateral position. In my experience, it can be down to two things: a cervical radiculopathy, which is to say an irritation of a spinal root, or just a less-than-optimal lateral sleep position. Normally, sleeping on the side shouldn’t induce paresthesias, but for a person with increased nerve root sensitivity (i.e. cervical radiculopathy), the extended pressure could trigger something like a nerve impingement, which could explain the numbness you’re feeling. Maybe this article can help.
The naps you explained in the second to last paragraph sounds like a more curious case to me. From the way you frame it, it sounds a lot like narcolepsy, but it could just as similarly be the result of fatigue. Hope that helped! I’m glad you found my article useful.