I love this site so much. I learned that there are two typologies of shoelace knots -- one falls apart instantly (https://www.fieggen.com/shoelace/grannyknot.htm), and the other is as secure as a double knot. I also learned the fast way to tie shoes, https://www.fieggen.com/shoelace/ianknot.htm. The latter is fun, I have used it every day for decades and people are always amazed when you teach them.