Books · 1894
When angry, count four; when very angry, swear.
— Mark Twain · Pudd'nhead Wilson's Calendar

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Anger gets a countdown here, and the bigger the anger, the wilder the fix. Count to four first, the speaker says. If that fails, swear, which is the joke: cursing is the honest release valve when counting can't cope.
Context reviewed