Yes, NOW I understand. And this explains an observation I made, which is that my airplane only wants to go in one of 2 directions!

Let's say the wind is coming from North (call it 0 degrees). Let's say the airplane is heading towards the north. So, I am now aligned with the airflow. That direction, and the opposite one (south, 180 degrees, flying aligned with the airflow in the same direction as the wind) is the only OTHER direction my plane can wants to/can fly.

Oh, but that's not always true, I don't think. In fact there are times that I've been able to fly my plane at 30 degrees; 90 degrees; 270, and a lot in between. And most of the time, I got to that direction by turning (rudder, aileron, or combination) and once vector is established, I return surfaces to neutral. The plane seems like it is staying on that new heading, which is NOT the same direction as the wind. Unless there is a different definition of the term "aligned" then the airplane is actually flying in a different direction of the wind.

Just as in sailing, there is the "apparent wind" which is the wind direction that the aircraft experiences. This would be the resultant vector that is the summation of the wind vector, and the aircraft vector. This tends to make the apparent wind somewhere between the true wind and the aircraft vector. The nature of vector summation is that it is difficult for apparent wind to equal true wind.

Or is there something I'm missing?

Regards