If this is a real question, this talk explains the fundamental concepts of atomic operations in a couple of minutes.

The talk itself is over an hour long, as the use of atomic operations has a large number of pitfalls. The joke in the meme leans on a specific type of memory ordering guarantee, known as “relaxed” in C++ parlance, which can be a lot faster, but which is much more likely to violate the default assumptions a programmer may make about order of operations and visibility across threads.