Large user stories

Any idea to what may imply "stories" in large user stories?

100% of the times when we are engaged in an Agile implementation inside an organization, we hear developers say -- and mostly this comes from team leaders, that it's impossible to divide big chunks of work into smaller ones (it may be dealing with large user stories or the technical aspect of splitting user stories to tasks, or other variations of the same slogan: "we can’t divide it to smaller portion”). Not only that, it is often assumed that large technical assignments cannot be divided into smaller ones. It’s a ”one hundred percent thing” - At the early stages of the implementation the thought that this is actually impossible is very common. https://www.wechange.company/why-cant-i-divide-large-chunk-of-work-into-smaller-ones/article