Ronald Reagan often said “Trust. But verify” when negotiating with the Soviets.
More cynically during the early 90s, I used to say “trust not, want not” after combining that Russian proverb with “waste not, want not.”
Happily, I’ve lost my cynicism since then, but I still use the phrase as a reminder to never assume that all necessary things are in place: Airline reservations. Correctly formatted data sets. All business partners fully prepared for a Tuesday morning client presentation…
Double check with a smile. But double check.