I am going to shamelessly lift the following from the annals of time. I'm guessing a piece of writing that's nearly 400 years old is out of copyright by now - if it was ever in it to begin with.
A good five years ago (ish), I came across a work by Minamoto Musashi called Dokkōdō - to give it some context, roughly translated that's something akin to 'The Way of Walking Alone' (and variants thereof). It's nothing more than 21 pieces of 'advice' but it also happens to be 21 lines I took on board at a time when I was really tired of fighting a battle I was never going to win and then forgot about. So yesterday when I found reference to it again online, I raised my eyebrows at exactly how much of this I had taken in - for good or ill.
A lot of this has helped me out more than I ever thought it would, so I'm dropping it in here for prosperity - if you can mine one valuable nugget out of it, it will have served its purpose. To get the most out of it, you'll need to be smart though.
If you're going to embrace Zen as a concept then you need to think about it less. There's more spirituality involved in driving the car to your favourite album than there is in buying a statue of a deity you have no business hanging around with. More spirituality to smoking a cigarette under the stars than there is in lighting a candle and wearing robes and telling everybody how much you love them. Anyway - here. Do what thou will with it...
Do not seek pleasure for its own sake.
Do not, under any circumstances, depend on a partial feeling.
Think lightly of yourself and deeply of the world.
Be detached from desire your whole life.
Do not regret what you have done.
Never be jealous.
Never let yourself be saddened by a separation.
Resentment and complaint are appropriate neither for oneself nor others.
Do not let yourself be guided by the feeling of lust or love.
In all things, have no preferences.
Be indifferent to where you live.
Do not pursue the taste of good food.
Do not hold on to possessions you no longer need.
Do not act following customary beliefs.
Do not collect weapons or practice with weapons beyond what is useful.
Do not fear death.
Do not seek to possess either goods or fiefs for your old age.
Respect Buddha and the gods without counting on their help.
You may abandon your own body but you must preserve your honor.
Never stray from the way.
Some may not make much sense almost 400 years later but the vast majority do. Like I said... do what thou will...