Yes, it's the first working implementation before good boundaries are not yet known. After a while it becomes familiar and natural conceptual boundaries arise that leads to 'factoring' and shouldn't require 'refactoring' because you prematurely guessed the wrong boundaries.

I'm all for the 100-200 line working version--can't say I've had a 500. I did once have a single SQL query that was about 2 full pages pushing the limits of DB2 (needed multiple PTFs just to execute it)--the size was largely from heuristic scope reductions. In the end, it did something in about 3 minutes that had no previous solution.

Nah mate, you never do. Nor 500 1-liners.