at the moment (in past tense context)

Question

In 2001 I watched a great documentary about Shakespeare. And this was the reason that novel books attracted my attention. I was also learning English at the moment.

Is it possible to use "at the moment" in the story instead of "at that moment", or incorrect?

I probably found a good answer, quoted below, to my question but I am not sure as to its credibility.

"I wasn't feeling like it at the moment." is perfectly good English. The same as, "He wasn't working at the time." However, most native speakers would say, "At the moment, I wasn't in the mood to watch a movie." You don't need the demonstrative there either, although you can put it in if you like.

"at the moment" isn't like "now" that has to be replaced by "then" in the past. It works fine in any present or past tense.

A quote about using "at the moment" in the past tense from COCA corpus

Over the next several months I recorded many of Ricardo's chants until my tape recorder was destroyed, fused by a lightning strike. As this occurred immediately after Ricardo had summoned me to his presence and I had replied that I was busy at the moment, the event did not lessen his considerable pride or reduce his reputation as the most powerful shaman of the area.

A quote from Google books

I texted him back to tell him I was busy at the moment and that I would contact him the next day. He said okay and that was that. As usual I put that out of my mind so that I could give my date my full attention.

By WENDY RICHARDS - 2013

You can search for more in Google books using I was busy at the moment here.

Answer 1

"At the moment" implies a short time, as, he was bust at that moment. There is an expectation of change relatively soon after.

moment n. 1. A brief, indefinite interval of time.

If the time in the past lasted longer, you can use other prepositions regarding time:

during, at the same time, at the time, in the meanwhile, for the time being, while, etc.

Since your study of English was not momentary, I would use a phrase that connoted a longer time interval.

In 2001 I watched a great documentary about Shakespeare. I was learning English at the time, and this was the reason that novel books attracted my attention...

I'm not exactly sure how you are trying to link novel books with Shakespeare. Shakespeare mostly wrote plays and sonnets. If you are saying you were attracted to his work, you could say exactly that:

In 2001 I watched a great documentary about Shakespeare. I was learning English at the time, and for this reason I was attracted to his work/for this reason his work attracted my attention...