That creeping realization how the legacy code works.

The "it's not possible. They couldn't have... yes. Yes they did."

It should have a name

It does have a name. Legacy.

A crapiphany perhaps? The realization that something crappy works

It's not just legacy. I've seen some new code where a guy extracts a huge (several GB) table in Python, to then pass it through around 300 lines of code that basically adds a column that is the sum of 2 other columns, aggregate, get distinct rows, delete another column, and push it back to the same database in a new table.