Books
He blinked, like some knight of King Arthur’s court, who, galloping to perform a deed of derring-do, has had the misfortune to collide witha tree.
— P.G. Wodehouse ‧ Uncle Dynamite

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
A comic simile about a man blinking in dazed surprise. It pictures a storybook knight galloping off to do something grand, then running straight into a tree. The mock-heroic image makes the dazed blink look both ridiculous and a little sympathetic.
Context reviewed