There's miles between understanding pinning well enough to call `Box::pin` (a safe API) and understanding pinning well enough to call `Pin::get_mut_unchecked` (

There's miles between understanding pinning well enough to call `Box::pin` (a safe API) and understanding pinning well enough to call `Pin::get_mut_unchecked` (an unsafe API). When we talk about understanding pinning, we mean the latter.