Translation:Do you remember?
I was thinking this, but I wasn't fancy enough to think of it in Japanese! Bravo!
Am I the only one who's clueless about this comment? The 21st of September something?
It's a reference to the song "September" by Earth, Wind and Fire. Its opening lyrics are "do you remember the 21st night of September?"
Oh my gosh I was thinking about the same thing, but I really didn't think somebody would actually write it!! I love it!
It's just one of those things, Japanese people use 覚える (oboeru) in the present progressive form to mean "remember" when in English we use the present tense.
Why is this continuous? That's just how this phrase is set in Japanese? You wouldn't say 覚えますか?
て- form of that verb describes the continuous state. I had remembered it early and now I remember(know) it.
The irony is this is also the first chorus line of a famous Anison- Ai oboete imasu ka. This was the song that broke the Zentraedi in Macross: Do You Remember Love? And it appears in some way in just about every Macross series.