Be kind, be nice to people. There is no reason that justifies being rude. Ever. But be assertive if necessary (being kind to yourself).
Reduce impatience, cultivate patience. What is easy becomes difficult by your impatience. => Meditate! Learn to enjoy every moment for what it is.
Do what you love. It will inspire you, and give you energy (instead of draining it).
Love what you do. Identify some things that you don’t like doing and learn to enjoy them. => “How can I make this fun?”
Don’t take things too seriously. Most likely they don’t matter too much, and can be better dealt with from a patient + fun mindset.
Always learn new (difficult) things. This will keep you mentally sharp and healthy into old age.
Be comfortable with discomfort. The higher the growth potential, the more discomfort you will usually feel. By facing a fear / acting in spite of your fear you will 100% of the time be & feel more free afterwards. “Happiness is on the other side of fear.”
Work hard + smart. And don’t be afraid to look like an idiot / to “wear a white belt again”.