The "dissociation" or possibly "disassociation" you speak of is referred to as Depersonalization/Derealization. Experiences of DP/DR are very common. Most people experience these feelings periodically. Ruminating thoughts or thinking/renarrating outloud accompanied by feelings of DP/DR are commonly reported in depressive episodes and anxiety panic disorders, amongst many other various MH conditions. I would advise speaking with a Dr. or MH professional immediately if you feel that you/your symptoms are seriously a potential threat to your life!

"Dissociation" is "triggered" by unexpected external stimuli that is instantainously processed and interpreted as an extremely overwhelming traumatic experience or remainder of a past trauma, or misinterpreted as exactly the same as a past trauma. This is a defense of the mind that is generally sudden and automatically employed; almost like a killswitch. True "dissociation" is a systematic response not a choice.

"Disassociation" or "normal disociation" is a purposeful choice though at the time you may not realize that you are actually making a choice. This happens under many circumstances. It is what people generally describe as "zoning, spacing or tuning out". Most notably attributed to when external stimuli is underwhelming compared to the internal stimuli. Although, it can also occur when the external stimuli is overwhelmingly unpleasant/intolerable (known but unavoidable). When your brain becomes overloaded by the unpleasant external stimuli, your mind offers the following solutions flight, fight, or freeze. If physically removing yourself from or reacting to the environment is not possible, then your choices are limited to mentally/emotionally numbing yourself to your surroundings. Although you may not notice yourself making this choice, you are in fact purposefully doing this. In either circumstance this effect is gradual. When refocusing or "snapping out of it", you are fully aware that time has lasped and you can account for the reason. In true dissociation, you have no memory of anything that occurred during the time lapse external or internal and you may not even be aware of that any time has lapsed either.

Sleepwalking and sleep talking are attributed to a sleep disturbance or disorder if reoccurrent. They are not a form of dissociation because you are actually asleep for the duration of the episode.

Regardless of the cause if these symptoms or occurrences are frequent or new and you find them to be disturbing or potentially harmful to your daily functioning, health or life; you should speak with your GP as soon as possible.

Hope this information finds you well.
Best wishes,
Victoria