Example:
Without lifting my head from the pillow, I glanced at my watch. Two in the morning. Sleep still seemed faraway. I'd been staring at the maze pattern on the ceiling for hours, occasionally switching to the intricate window frames, and the floral curtains of the window. My mind always seeks for complex figures and shapes when I'm still, in the dark. I'm not sure why. Maybe my head's constantly trying to make sense of things, even if my body is completely relaxed. It's something I can't avoid.
So after lying there for another hour, I gave up. I dressed, grabbed my keys, and went out for a walk.
So I could have written it like:
My mind always sought for complex figures and shapes when I was still, in the dark. I wasn't sure why. Maybe my head was constantly trying to make sense of things, even if my body was totally relaxed. It was something I couldn't avoid.
I don't mind if the narrator is still doing that. It doesn't affect much the story. I just want to know which way reads/flow better. Does it feel jarring when you read the last part of the first paragraph (present tense) and immediately jump to the second (past tense)?