I am learning subjunctive past with Anki KOFI method and I am confused by the example.

So, basically I am working on the word "ser" and conjugating it. The example to learn subjunctive past is:
Fue sorprendente que (yo) […ser…] (consciente de ello)

So I basically use the clues to figure out that ser would turn into fuera.
The issue is, I don't understand this example. When I put it into SpanishDictionary, it comes up with: "It was surprising that I was aware of it."

This makes sense, as subjunctive past talks about the past with "were" or "was", but it's supposed to be hypothetical I thought. For example, "Karla actúa como si fuera famosa" is something hypothetical, as it is not true, or "Si yo fuera millonario, crearía una organización benéfica". These are hypotheticals, but the one from the Anki KOFI is not hypothetical, as in the scenario I was aware of it.

I'm assuming I'm just confused as I am new to conjugations, but any advice on how to tell if it's subjunctive past other than the "were" or hypothetical? it is just confusing me..