It is necessary to know such things exist, but expected that their details will be looked up when relevant. Some people write low level concurrent code all the

It is necessary to know such things exist, but expected that their details will be looked up when relevant. Some people write low level concurrent code all the time, and they need to be up on all those details all the time. But many people only do so intermittently, and they only need to be aware of the existence of tricky details in the space, and have the capacity to get up to speed on them.