I read your question twice, but I alro "read" it two different ways. The first way is that you are having trouble remembering 'how' to knot it, and the method described above works best for me, as well. The second way I 'read' was that you are having difficulty remembering where you left of. In answer to that, when I am quilting small pieces, I tie off several knots at one time, then I am ready to go to the next one without losing my place. If I have to leave off and come back to the quilting later, I put my needle or a straight pin in the place I want to pick up again.
Hope either of these are of help.
nanac