Mrs P had what looked like a simple problem. There used to be a screw holding the light cover in place on her cooker hood that had dropped somewhere behind the cooker. She'd decided that it was lost, so she had a scavenged collection of screws plus a brand new pack for Holdilocks to use to keep the plastic cover in place.

Holdilocks started with the smallest screw which was too small to stay in the screw hole. He worked his way up through the screw sizes with none of them fitting until he tried the largest one, which was too large to fit in the hole. As there was no "just right" option and the cooker hood was made of sheet metal, Holdilocks decided to use the Holdilocks principle which says:

If the Goldilocks principle doesn't work and there is no "just right", then judiciously try more power to make things hold together

By defining and using his own principle, Holdilocks made the large screw fit by increasing the size of the hole and the hold on the cover became just right.