
Because they are the knights of summer
and WINTER is coming.
Game of Thrones Season 2, Episode 3

And every WINTER that ever came
has ended.
Game of Thrones Season 7, Episode 1

Winter is coming.
Game of Thrones Season 5, Episode 3

as soon as the WINTER storms pass.
Game of Thrones Season 8, Episode 4

But WINTER is coming.
Game of Thrones Season 5, Episode 5