I guess I understood what a delimited continuation is!
The examples in this talk by @wingo just clicked: https://youtu.be/uwiaT3MoDVs?t=1236
I love "a historicall accident" parts :)
If you have other good learning resources on the topic of continuations, please share.
@abcdw @wingo I'm not sure it qualifies, but Section 5 of this draft describes how to add delimited computations to a language using a meta language that can express delimited continuations
https://people.rennes.inria.fr/Alan.Schmitt/papers/programming_draft.pdf