verb tense: does anybody take note?

I’m wondering how much the average reader notices about the mechanics behind the story. In particular I’m wondering about verb tense.

In the spoken language, a shift from telling a story in past tense to the present tense is a big narrative flag. For example:

You know how I went over to see my grandma yesterday? So I walk in and she looks up and sees me standing there and she says, Joyce, she says, come over here and help me with my buttons, I can’t reach and I’m late for work. And I’m thinking, grandma’s around the bend, she’s talking to me like I’m my mother. Like I don’t got enough problems. So I grab the phone and call the house and I say to ma, get over here, double quick.

This short bit of dialog starts off in past tense and quickly shifts to present, which signals the narrator’s degree of involvement in the story she’s telling. Present tense brings in a dramatic edge.

Now, everybody does this. You do it too, when you’re telling a story in which you’ve got some kind of investment. There’s a vibrancy to using the present tense this way. And the effect is there whether people actually notice the tense shift or not. It functions below the level of consciousness, for the most part.

In writing I shift into present tense for the most important scenes, the ones with the biggest emotional punch. I don’t think about doing it, it just clicks in.

When I’m reading I take note of that kind of thing. Tenses shift, POVs turn on a dime, exposition, whatever tricks the writer pulls out of the bag, I usually take note. And I’ll think to myself, nice transition or that was a little awkward. This kind of note taking is second nature and barely slows me down unless it’s something egregiously awful or stunningly effective. I would like, sometimes, to not take note, but it’s almost impossible. My father-in-law was a structural engineer at British Aerospace for fifty years, and he can’t just sit in an airplane. Everything has meaning to him, every sound, every movement. It’s all noise to me, but not to him.

So I’m wondering if you all (the ones who don’t write for a living) take note of what goes on in terms of story mechanics as you read, or if all that just stays below the level of consciousness.