I remember contracting for IBM in the 90s and we had a huge performance boost due to caching and, like the anecdote in this post, there was a slight chance of something going out of date. The IBM guys said "no thanks, IBM prefers bullet proof over fast".
"You didn't pay me $1k to press three buttons; you paid me $1k for knowing which three buttons to press."
EDIT: oh, i see a version of this was already posted in another comment :)
When I asked my Dad how long something took, he'd say something like "2 years and 20 minutes." 2 years to get around to it. Mom took his habit into the real world and published an ad for the company with a cut out "Round Tuit" and copy, "How many times have you heard someone say, 'I'll do that when I get a round tuit.' Now that you have your very own Round Tuit, there's no limit to what you can accomplish!"
Round Tuits were cut out and appeared on walls all over town.
* The oil was still <5k mi old. People are funny.
Bulletproof typically means rigid in design. Trading one bag of worms for another.