Write things down. Revisit them. By this process you will discover that you were not the person you were even five minutes ago. Take that to heart.
Don't be a jerk. Moreover, don't pretend you don't know what a jerk is.
Measure twice, cut once. And measure from different directions if you can.
To tell good from evil, give it power. Evil keeps power for itself. Good gives power back to you.
It's OK to walk out of a bad movie or drop a boring book. Life's too short to waste on things that aren't for you.
That said, what was boring at nineteen might be enthralling at thirty-six. Allow for the possibility that you have evolved.
Existence is a learning experience, not a morality play.
A difficult truth is always better than an easy joy, but that doesn't mean an ice cream cone after dinner is a sin.
Suffering is private. Never judge someone else for being in less pain than you, or more pain than you.
Break the rules rather than do anything outright barbarous, but also own the consequences of doing so.
There is always something worthwhile in the present moment, even if seems like a terrible moment. You owe it to yourself to find it.
Shared taste is not necessarily an indicator of shared values. Divergent taste is not necessarily an indicator of divergent values.
Don't worry about what other people think of you. But you are permitted to defray this rule if the people in question cut your paychecks. Just try not to defray it forever.
Be yourself, but not to the extent that you're living all over the guy next to you.
Technology is neither good nor bad; nor is it neutral. (attributed to Melvin Kranzberg)
Money can't buy happiness. It can buy remarkable simulations of it that are good enough to fool the inattentive. Don't be one of those dopes. Insist on the real thing, the one that has no pricetag.
Taking pride in being an asshole is slim pickings indeed.
Never confuse a bid for immortality with the childish fear of death.
Remember: they can kill you, they can besmirch your name, they can destroy everything you've ever done and ruin the lives of everyone you've ever loved, but that's all. (Paraphrased from Henry Rollins)
Never strong-arm anyone else into learning any of this. They have to get it for themselves.
Also, Milton Glaser's Rules are worth remembering:
You can only work for people you like.
If you have a choice, never have a job. Have a vocation, or a livelihood, but never a job.
Some people are toxic; avoid them.
Professionalism is not enough; the good is the enemy of the great. (My way of putting it: Always play that much more over your head.)
Less is not necessarily more. Just enough is more.
Style is not to be trusted. Catering to peoples' tastes now is to cater to their whims, and whims change.
How you live changes your brain. Live richly and diversely. See rule 4.
Doubt is better than certainty.
Solving the problem is more important than being right.