So now your case seems much less impressive

Just sharing data points here, the impressiveness was in your head to begin with :) You said memorization is labour intensive and I don't find that to be true.

Holding a list of vocab words in my head for an hour based on a few minutes of study is something I might be able to do too, depending on the length of the list. Terrible approach for long-term retention, though.

Well, I didn't say I forgot them in an hour and those exams did include conjugations. We had bigger exams including grammar on top of those vocab exams, and I didn't really study for those excluding the classes. Earlier vocabulary was naturally needed for the later classes. The lack of serious initial repetition could be the reason I don't remember them 10 years afterwards, but I doubt anything can be forever remembered without repetition and long term retention really can't be called the labour intensive part of memorization.

I have other experiences that suggest initial repetition for a couple of months doesn't help much in the long term.

English spelling is the worst.

In Finnish you spell it almost exactly the way you say it and I don't think many languages do that. I've always enjoyed English and one of the reasons is the spelling and the pronunciation. Vocal acrobatics was one of the reasons I wanted to learn Russian for fun :)

An example from medicine: I make flashcards in bursts, and sometimes make hundreds of them in a day. At the end of the day I usually remember something like 90% of them on the first try. Should I call memorization difficult?