two quotes about keeping calm and carrying on
“Always behave as if nothing had happened, no matter what has happened.”
– Arnold Bennett
“Perhaps in the end there is little difference between keeping one’s head and pretending to do so; perhaps the effort required to feign unconcern and control over a situation itself imparts a measure of control.”
—Michael Chabon
[I found both of these over here, one recently, one a long time ago]