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.

“the more he became inside me”. Oddly arousing, number one.

It makes sense. Picard as a character changed a lot over the series.

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.