I ask Bryan: would he still take the advice that his 12-year-old self might have taped to a door?
My answer: Definitely, especially if my time capsule from 1983 contained advice about how to treat kids. You can say "hindsight bias" all you like, but many of the life lessons I've accumulated pre-date my 12th birthday.
One of my all-time favorites: "Do not direct anger at others; lashing out is at best a short-sighted strategy that makes enemies and discourages honest feedback." Another: "Don't talk to people about things that don't interest them." Still another: "Dare to be different." 25 years later, this is all still good advice.