Well, since the notches are flat, you can't poke the thread into the notch like threading a needle. You've got to lay the thread near the notch, applying gentle downwards pressure so it lays flush against the bobbin case, and then pull a bit sideways towards the notch, so that the downwards pressure will guide the thread as it slips into the notch. 'Draw' is the best single word for that motion, but you're right that it isn't very intuitive.
Kliban Qat
August 2009