I'd say that's normal for some of us.

I don't particularly think its problematic unless you are having nightmares or terrors but it can get you in a stink sometimes. My bf will swear he told me something but really he told my sleeping self and i have no conscious recollection.
And sometimes I'm saying something funny or mean and he thinks I must be sleep talking and literally will have to shake/pinch/pour water on me to see if I'm asleep or not.
I tend to get very mad when this happens.
THats why its so important to be under doctor care that makes sure you are not overmedicating and contributing to the problem or using the wrong type of meds for sleep

I do that a lot and normally hold a full convo of gibberish to. I'll be talking about the universe
It's common I think.

I can do that too

Exactly - many time it's the reaction, there are times I don't dream, most of those time I don't know I fell asleep, until I see the reaction of those around me.