Holy cow, I wrote a book!
This is a story from a friend of a friend,
which makes it probably untrue, but I still like the story.
One of my colleagues jokingly suggested that we could speed up
our code by adding these lines to our project
#define EnterCriticalSection(p) ((void)0)
#define LeaveCriticalSection(p) ((void)0)
I replied, "You think you're joking, but you're not."
According to legend, there was a project whose product
was running too slow,
so they spun off a subteam to see what architectural changes
would help them improve their performance.
The subteam returned some time later with a fork of the project
that they had "tuned".
And it was indeed the case that the performance-tuned version
ran a lot faster.
Later, the development team discovered that part of the "tuning"
involved simply deleting all the synchronization.
They didn't replace it with lock-free algorithms
or anything that clever.
They just removed all the critical sections.