Off-by-one-errors Memes

The joke is hiding in plain sight—just like that duplicate cache invalidation entry. Notice how the list claims to have "three" hardest things but actually lists five items? And cache invalidation appears twice? That's the meta-joke about cache invalidation being so hard you can't even remember you already listed it. Meanwhile, "Threlti-Muading" is just "Thread Loading" with a naming problem, proving the point about naming things being difficult. And the cherry on top? The list itself has an off-by-one error by promising three items but delivering five. It's recursively proving its own point!