Are pussycats stupid?

My sweet kitty is a kitty that lives in home, she has never been an ‘out’ cat.
The only times she is out is when I take her for a walk on the balcony or the gallery of my apartment building.
We walk to the corridor where the elevator is situated, I open the door of it and we are in the corridor.
Beside the elevator there are also stairs, leading floors up and down.
Now sometimes she takes the stairs to one floor down and walks to the door (which is closed) to the gallery and starts a ‘panicky’ meow (I assume it is panicky because the door isn’t open and she can’t enter the gallery back to her house (which isn’t on that floor of course)).
Now my question is this: Did my pussycat already forgot, after seconds, that she walked the stairs to a down floor? is she stupid?
Any cat memory specialists around?