Unlike other pieces, sometimes moving the knight 1 step back can lead to 2 steps forward into an attack.  Here is an example where a knight back to h2 leads to a powerful attack on the kingside.

I would have done 21. Nh6#. It helps your pattern recognition, if you make the less common move.

Yeah being that it was just a 2 min game I guess I was concerned with my time.  Good advice.

Good game!

nice!

Another good one