While I am doing something that does not require optical focus on the text, such as walking, cleaning, taking a bath, and so on, my brain keeps making a draft of English sentences that are partially related to work.
They are, usually, potential responses to emails/chats/comments that I will/might receive tomorrow/next week. Sometimes this preparation pays off. Sometimes not. Regardless of whether it is hopeful or not, I cannot stop doing it because it starts automatically in the background when my brain decides "I am idle now."
About ten years ago, I purposely started doing it as a kind of English practice. Before I knew it it became a weird habit. I am not saying I am thinking things in English nor I am living in English. Because, you know, writing emails in your head during washing your hair sounds like a workaholic. Not as natural as I am thinking things in Japanese.