When you act without theory you can find yourself beating your head against the wall, in ways similar to this woodpecker bangs its head against this sign.
This bird may have copied the pecking behavior without understanding the theory. Pecking steel won’t lead to it uncovering insects to eat. Alternatively, it may be pecking to make noise and attract a mate or tell other woodpeckers this territory is claimed. If mates and others acknowledge the metal pecking noises then the behavior may be rewarded (the noise is louder than pecking wood so it may even be an innovation with improved results), if not, the beating its bill against the sign is wasted effort.
If you don’t understand why you take action you will find yourself wasting effort. You must have a theory that you can test in order to test what is working, what changes actually lead to improvement and to learn. If this bird wants to find food it will discover this method isn’t effective.
I wrote about a similar example before: Experience Teaches Nothing Without Theory.