🚀 go-pugleaf

      a variable that i can place in a text, needs to be visible under text
      variables -> define. So first i define a variable, then i make an instance
      of it at the location needed right?




That's right.

      I thought that Last Page Number was a variable that was always present
      and therefore did not need to be added before using it.




If you delete it without any documents open, you'll never see it in documents you create afterwards.

      Are these "demo" variables from Adobe included in the document in any
      way




These demo variables are included in all new documents you create. Text variables behave just like styles in this respect. Styles created in a document are available only in that document. Styles created with no open documents are available in all documents created later.

      why have you deleted them?




Because I have no use for them, and I like to strip everything unnecessary from documents.

Peter