My question was migrated from SO, I linked my SO account to Meta-SO, but I can't edit or mark my question as answered. Is it [closed], and therefore should I just forget about it?
Reply back from firstname.lastname@example.org
There is no current way to re-own a question unless you had an account on the target site prior to the question migration.
This is something we plan to get to in the near future, however.
The data in the database contains the keys necessary to re-associate, so it is possible to fix this after the fact.
So the answer is probably forget about it in this case.
Your accounts remain unlinked. Try linking them again.
You have different UserIDs (131563 here on Meta, 133544 on SO). This means that you're two different people (to the system, you haven't developed schizophrenia that I'm aware of), and therefore, the closed question has a ghost user.
Methinks you have found a bug.