This is actually somewhat more than a quibble, because I cannot imagine why anybody gets this wrong, yet you see it all the time. Well, it seems like all the time, anyway. Too often, for sure. Here it is:
Direct thoughts are NEVER in the past tense.
Take the following passage, for example:
I’d heard of fallen angels, of course. Everyone knew they’d started to appear over the past few years. They looked just like regular people, except you could just tell. They were brighter, somehow. Or darker. More vivid, more real. And fallen angels might appear anywhere; you’d think they’d be drawn to New York and LA, but word was a fallen angel was just as likely to stroll through downtown Poughkeepsie or, say, Glasgow, Montana.
Glasgow was officially the middle of nowhere. It said so right there on Google, so you knew it was true. Compared to Choteau, though, Glasgow, Montana, was a happening place. Here in Choteau, we didn’t even have a separate high school. Every grade was right there together in one square brick building. It wasn’t even a big building. Definitely not an interesting building. Boring in every possible way, that was Choteau’s school. Especially its high school.
That was the last place I would ever have expected to see a fallen angel. But there he was. Not a student (I knew you would think he was a student). He was our new teacher, that was the announcement. He was going to teach history and Latin and, who knew, probably coach basketball. Our school always liked to hire teachers who were willing to coach as well as teach. Or coaches who were willing to sort of handwave teaching. Otherwise we’d never have had enough faculty to do everything.
But it didn’t matter to me that Mr. Acacius was a teacher. The minute I saw him, I thought, My God, he was something. He was … just something out of this world.
Upon hitting this line, I am immediately jerked hard out of the story. That’s what you thought, huh? You thought in the PAST TENSE? What, you see a guy and you immediately think to yourself HE WAS SOMETHING, do you? That’s how it works in real life, that’s for sure, all those internal thoughts that stream through my brain all day are naturally in the past tense. I come home and see all the dogs but one and think, “Where was Dora?” Because that totally makes sense.
Obviously this is ridiculous. No one ever thinks to themselves in the past tense. You see a guy and you think, “Wow, he IS really something.” A dog is missing and you think, “Where IS Dora?” It is not even possible to think to yourself in the past tense. I doubt anyone in the entire history of the world have ever thought to themselves in the past tense.
I do not mean to pick on paranormal romance AT ALL, because you see this everywhere. The phrase “He was so hot” jumped into my head as an example, and all those high school paranormals came to mind, so I wrote a passage that could belong to that kind of story. But I have seen this type of mistake in all kinds of SFF. I have also … not to throw stones and in fact I don’t remember who it was … but I have had a copy editor try to switch a direct internal thought from present tense to past. (I wrote a little note in the margin as well as STET, in an effort to make absolutely sure the internal thought appeared in present tense.) (It did.)
This applies, of course, only to direct internal thoughts, what one might call internal monologue, except so often it’s just one line, so that’s not much of a monologue.
Certainly you can write:
Would he ever notice me? I didn’t know, but I could hope.
He was the first person, I thought, that I had ever been completely honest with.
Both of those are fine. Neither of these is at all the same thing as the original passage above.
In the first of these two cases, the author is writing in a more distant first person and is not providing thoughts as the protagonist thinks them. The whole story is past tense. In the second, the protagonist is reporting her own thoughts after the fact and that is why the sentence is in the past tense.
The type of internal thought I mean, the only kind I mean, is the type of direct internal thoughts the character is thinking at that very moment of the story. That is the kind of thought you put in italics to set it off from the rest of the paragraph. Those thoughts should always, always, be in the present tense.