Leonard Nimoy had a similar experience playing Spock. Writing his autobiographies “I am not Spock” 1975 and “I am Spock” 1995 as an example of the struggle.
On a related note, Nana Visitor, after DS9 ended, had some difficulties with new roles. She was unwittingly channeling Kira and ended up being repeatedly told by the director to not. She also confessed to occasionally having Kira’s nightmares.
It makes sense. Picard as a character changed a lot over the series.
Unfortunately, as Patrick Stewart imposed his interests and personality on the character, Picard became less and less the cerebral captain whose leadership style I admired and wished to emulate.
I’m not sure Patrick Stewart has ever understood the qualities in Picard that captivate so many in the peak midrun of TNG.
While I am not as harsh on Picard S1 and S2 as other people, I still have complaints about how silly it sometimes got (the vastly differing degrees of caring about messing up the timeline by changing details in S2 was confusing, sometimes a small change was bad, other times characters just made big changes…).
What I will say about Picard as a whole though, especially in S1 and S2, is that how Picard’s character grows and changes felt really well done.
spoiler
Picard’s mother committing suicide and him feeling responsible in a way, while also remembering his dad as this kind of villain as a way to wall off his emotional trauma and that then impacting him for the rest of his life felt very believable to me.
As a whole I definitely enjoyed Picard, it makes it more fun to watch TNG with the retrospective knowledge of who Picard becomes and what Picard isn’t talking about all those years on TNG.
“the more he became inside me”. Oddly arousing, number one.