Late night Knight actions

Have you ever played a game where your last piece finally started moving from the beginning position after a lot of moves ?
Here in this fresh game the knight on b1 was waiting patiently for 35 moves, and then became the hero of the game :)
And ironically Stockfish gives my 36.Nb1-d2 a question mark, suggesting f4!! :)

Well yeah f4 probably would've been better because of Nd2 Bxd2 I guess but nice knight. just was waitin there

35 is a loooong time for such an entrance.

I think the question mark is because Stockfish saw that the knight might be stronger than the bishop in this type of endgame, so you should prevent black fom trading on d2 immediately.