It is videly discussed if the different deities, figures and creatures in our mythology, fairy tales, songs and culture can represent multiple things, events and processes on different levels.
There is hardly no exaggeration when we say that all native Norwegian children have been growing up with Trolls. In all shapes and forms. They are a big part of our culture, in art, in small or even big figures (handmade or bought) at the shelves in private homes and cottages. We see the Trolls out in our Nordic Nature, in mountains, stones, snow covered trees, hills, in foggy weather and winter storms. (No, not in scary "human shapes" for real, but at a more subtile level). We even have a known word for this sublime, grim beauty - namely "Trollsk". It is a description of a state of mind. It is difficult to frame it with words, but it is the state of mind that artists like Theodor Kittelsen incapsulated in his drawings.
"Skogstroll" (a Forest Troll) by Theodor Kittelsen
Already now we understand that Trolls represent multiple things, on different levels.
If we take a look at the etomology of Norse - Troll, it is related to Ettin (Norse: Jǫtunn, Jötul etc.). The word relates to a "scary" creature, a devourer, a big eater. They can be greedy. They are primordial powers, often very strong and not very sofisticated. They are old, very old, and some even "all knowing".
They are Nature, wild and untamed. They are often "early versions" so to speak, the same way that dwarves are "uncompleted" things. Thus, the Trolls come in different forms and shapes, as Mountain Trolls, Sea Trolls, Water Trolls, Forest Trolls etc.
"Det rusler og tasler" by Theodor Kittelsen
When the water fills the crack of a mountain and shapeshifts to ice, nothing can stop its primordial strenght. It will crack the mountain open, and demand its space... Like a winter storm can lead you astray, and take your life swiftly, if you do not adjust to it and outsmart it.
The Trolls are duality. They both help you and can swiftly kill you. They can be beautiful, but at the same time scary.
"Hulder" by Theodor Kittelsen
Huldra (a female Troll) in the form of a beautiful lady (with a tale hidden) will attract you and lure you into her cave. Yes, you will enter the realm of death...
Just like Natures duality, the Ettin powers are also to be found in yourself, at a personal level. It can be recognized as greed, envy, gluttony, un-kindness etc. These primordial powers are not in sum evil per se, but necessary indeed, at a managable level - balanced by the powers of the Gods. Yes, there is no coincidence that the Gods are related to these primordial powers, that their ancestors and even partners and counterparts indeed in many cases are Jötnar. There is no coincidence that Þórr (Midgard's Veurr, your willpower and lojalty, gravitation and deity for weather, wind and crops) in the myths fights for his life force, slaying Jötnar and gets re-born. Þórr is not only a personification of a human child, he is the same powers in you as well. There is no good or evil. There is only pagan balance.
"Troldet som grundet over hvor gammelt det var"
(The Troll that pondered over how old it was)
by Theodor Kittelsen
The Trolls are "twins", connected to the Gods. They are the old Kings and Queens. They must be overcomed by the Gods, by a new King or Queen. They are always outsmarted, fought and slain in our myths and fairy tales - and the eternal metals and items of their riches - the memory, the life force is achieved by their successors. Their "all knowing" memory is transferred, just like in the myth Alvissmál and others where Þórr enters the cave of an Ettin or a Dwarf, or when Askeladden (the Ashlad) outsmarts the Cave Troll and acquires the same.
Yes, you find the Trolls at every pattern of Nature, in yourself, in your quest for glory, in your fights for loyalty, kindness and modesty, in the meetings with others, in wild and untamed Nature with all its sublime darkness, beauty, dangers, horrors and mercilessness. The same way a a newborn child has been fed by the devourer and ancestor in its cave, been fighting the primordial powers and replaced its old slain King, its ancestor and twin - re-born.
"The Troll alone
takes sudden revenge;
the coward never"
- Grettirs saga