today I learned about Transclusion (https://tiddlywiki.com/#Transclusion)
So this is something I did not understand when I started using tiddlywiki: the tiddlers are meant to be quite short. But, I thought, sometimes I need all the information at a glance in one tiddler.
So it was only today that I learned that you can cut up a big tiddler into smaller ones (ctrl+e / "excise") and use transclusion. which means the content of the new tiddler is shown in the old, as if it was one big text.