Whenever The Doctor regenerates into a new Doctor, does the previous incarnation essentially die, with only his memories being absorbed into the new Doctor, or are the previous Doctor incarnations/personalities still ‘present’ somewhere within the Doc's psyche? Similar to how Bruce Banner has several different Hulk incarnations within his psyche (Savage Hulk, Gray Hulk, Professor Hulk, World Breaker Hulk, ect).
I’m new to the Doc Who lore, but I have to ask this due to hearing/reading something about the first Doctor being referred to by a later Doctor as “The Grumpy/Grouchy” one. Which, to me, indicates different incarnations with the novelty of having shared memories...
Any help would be greatly appreciated.