Where large sums of money are concerned, it is advisable to trust nobody. — Agatha Christie

Where large sums of money are concerned, it is advisable to trust nobody.

Author: Agatha Christie

Insight: We want to believe people are fundamentally good, especially people we know well. But money has this strange property—it reveals character in ways that nothing else quite does. A person who'd never steal from you in small moments might make a different calculation when a large sum appears on the table. It's not always about villainy. Sometimes it's just that the stakes shift our thinking, our rationalizations, our sense of what's "fair" to take. This doesn't mean becoming paranoid or treating everyone like a criminal. It means building practical guardrails. Put agreements in writing. Use escrow. Have multiple people sign off. Don't rely on handshake deals or "I trust them" feelings when serious money moves. Even the most honest person benefits from structures that remove temptation or ambiguity. You're not insulting them—you're protecting the relationship itself. The twist: Christie isn't saying people are rotten. She's saying that big money creates pressure that bypasses our good intentions. A friend who'd never disappoint you in normal circumstances might genuinely struggle when financial desperation or opportunity presents itself. Build systems, not accusations.

Source: Hercule Poirot's Christmas, 1938