Per your downvotes - I used to hate jokes on Hacker News and downvote them when I saw them, but I've become more ambivalent. They're a way of amicably sharing culture and experiences with other engineers that transcend any differences in age, gender, race, background, etc.
It's barely even a joke to me anymore -- it's just too real for me to laugh.
(Cache invalidation is essentially the same problem as managing mutable state -- "Out of the Tar Pit" frames mutable state as either essential or incidental, the latter being rederivable in principle from essential state. Incidental mutable state is no more and no less than a cache, and usually one with an informal and undocumented invalidation policy.)
(And naming things has a very real technical counterpart in addressing, which comes up obviously in networking, but you can also see its shadows in quite a lot of concerns around architecture and modularity.)
The formulation of this joke I tend to see is,
The two hardest problems in programming:
(1) cache invalidation
(2) appropriately naming things
(3) off-by-one errors