Speaking Voice vs. Mind's Voice

Ada from the Piano (1994) says at the beginning of the movie:
"The voice you hear is not my speaking voice, but my mind's voice."

At that time, I thought it was a cute way to make a film about a mute person. As I'm getting older and older, I keep revisiting this idea.

When I was younger, I was less educated, less sophisticated, but fearless in speaking my mind. If I had an opinion, I would express it. Nothing would hold me back. So my speaking voice, and my mind's voice were almost the same. Not today.

At this point in my life, I have to preview/censor everything in my mind before it comes out of my mouth. I have a practiced pitch (deeper than my childhood voice), a slower drawl (many feedback about me being incomprehensible over the years), a practiced hard pronunciation of "T" and "F" (the ones I never pronounced correctly), and many words removed from my vocabulary (you try asking for a "rubber" and not an erasure at a biology test (darn Americans)).

One could argue that my mind's voice has become that way. But I know better. Wait 20 years, when the censorship dies down.