To the old investors out there with 40+ years in the market, what would be your best piece of advice?

For those who have been in the market for many years and have navigated numerous ups and downs, what advice would you offer for achieving greater success in investments?
Personally, I've learned that treating my investments with detachment, as if I were a disinterested observer reading the newspaper, has been effective for me.
I've found that enjoying following the markets has sparked my curiosity about international politics and the economy, reading balance sheets, and understanding better how the world is moving, ultimately benefiting my investment approach.