I was that way for a few decades when I was still working with U.S. based companies and speaking a moderate amount of English on most days. However since we moved down here outside of San Quintin, the only real English I get anymore is here on Facebook and that is only read/typed and not spoken. I probably have gone months at a time without actually speaking English these last 15 years and that has probably influenced why my brain made the transition to 24/7 Spanish.
What’s amazing about the brain is that I can listen to 2 side by side conversations, one in English and the other in Spanish, and simultaneously comprehend both conversations. That is something that I only really perfected in these last several years and I think it’s because my brain translates the English to Spanish, making it easier to comprehend the 2 conversations in the same language (in my head) in real time.