Drop the sentimental crap and swap it. That 100k milestone is just a number on a dash, not a personality. A numbers matching L24 sounds nice at a car show but sucks when you're trying to merge onto I-5. You'll never get that $4,500 back in resale value, but you'll feel it every time you hit the gas. The purists aren't paying your gas or fixing your carbs. Keep the old motor in a corner of the garage if you're that attached. Drive the damn thing and enjoy it.

That 40k rows thing made me laugh cause I did almost the same thing with a customer list in Portland, pulled 12k records and my manager just sighed and walked away. I get the value of breaking stuff, but I think tutorials exist so you dont waste a whole afternoon on a mistake that one explainer video couldve saved you from. The real lesson isnt the wrong join, its learning to check your row counts before you show anyone, that stuck with me way more than any CTE. Breaking things on purpose sounds fun but in a real job that clock is ticking, so maybe break things in a sandbox database instead of production.