[thelastgallon]

There are 2 hard problems in computer science: naming things and cache invalidation. Cloudflare writes about how it deals with the first one.

[aa-jv]

3 hard things: you missed counting things.

[Stratoscope]

The classic version...

There are two hard problems in Computer Science: naming things, cache invalidation, and off by one errors.

[stavros]

The joke only works if it's still two things.