wherein = in which/what
therein = in it, in that/those
whereby = by which/what
thereby = by it, that/those
*hereby = by this/these
whereof = of which/what
thereof = of it, of that/those
*thereafter = after that/those
*therefore = for that (reason), for those (reasons)
In all these words, "where" correspond to "which", "there" to "that", and "here" to "this".
If I remember correctly (the etymologists are free to contradict me!), the words "there", "here", "where" in the earliest phases of the language were inflections of "that", "this", and "which"/"who" similar to (but of a different grammatical case from) the surviving series "who" -- "whose" -- "whom".
Imagine a situation wherein we are at sea.
The box, and everything therein.
The events whereby we found ourselves at war.
Bombing and all the devastation caused thereby.
*You have been read the riot act, and are hereby ordered to disperse.
*Court summons. You are hereby [by this very summons] summoned/ordered to appear in court...
I know not whereof I speak.
So many exams, and the grading thereof.
*He quit, and never worked thereafter.
*I think, therefore I am.
Now try to figure out "whereabout(s)" (place) and "thereabout(s)" (place or time).
Student or Learner