Do your shoe laces come untied a lot? Mine do, so this actually makes me feel better!
Shoelaces tied the conventional way, using the "bunny ears" technique taught to kids, failed every time they were tested, but the so-called “strong knot” came apart in only half of the 15-minute lab trials at the maximum weight.
To make a strong knot, cross the left lace over the right and pull it through the resulting loop. Form both the right and the left lace ends into loops and wrap the bottom of the right loop around the bottom of the left.