The joy of self-regretfulness
To me, any thought that inspires humility is a good thought. Try this one on for size: Ever read something -- or done something, or wore something, or believed something -- ten years ago that you now look back on and cringe?
Think about it. We tend to naturally feel rather mature and "in the prime" at any given moment. Yet the self you were a decade ago, who now makes you cringe, is in all-too-real continuity with the same person you are today. And this is the same person who's provide cringe fodder for a decade from now.
A good thing to keep in mind when tempted to take our precious opinions and current ways of living too seriously and the good Lord and his gospel Way too lightly.
Only One among us the same "yesterday, today, and forever" (Letter to the Hebrews.)