Every possession and every happiness is but lent by chance for an uncertain time, and may therefore be demanded back the next hour.

Nothing you hold is held permanently. What you own and what makes you glad arrived through some mixture of effort and luck, and the luck part can be withdrawn without warning or fairness. Naming that is not pessimism; it is the reason gratitude has any weight at all. A thing you might lose is a thing you actually look at.

Pick one ordinary good in your life this week and attend to it as though it were on loan. Say the thanks you have been saving for a better occasion. If loss does come, it will not find you having taken the years for granted.