I answered their questions 'to the best of my knowledge'. [=I gave the best answers I could based on what I knew, but I might have answered differently if I had known something else]
No one arrived late 'to my knowledge'. [=I am not aware that anyone arrived late, but it is possible that someone arrived late and I don't know about it]
They went on vacation, 'safe in the knowledge' that the farm would be well cared for while they were away.
(..) ... were lost. History became legend... ...legend became myth. And for two and a half thousand years... ... the Ring passed out of all knowledge. Until,when chance came... ...it ensnared a new bearer. My precious. The Ring came to the creature Gollum... (..)2001 The Lord of the Rings: The Fellowship of the Ring