When I was six or seven my older brother untied my shoelaces when I wasn't looking, and I tripped on them and almost fell down. This was apparently a traumatic event for me since it has affected my behavior ever since. I've double-knotted my shoelaces every time since then, usually remembering why. For about the last 57 years. When I was about 12 the same brother tried it again and failed due to the double knot. It was a moment of triumph.
But the double knot still sometimes comes untied somehow so I've never been entirely happy with it. Maybe if I take the effort to overcome my muscle memory and learn Ian's knot, it will quell the PTSD from being victimized at a young age and I can find inner peace.