1. I am subject to aging; I am not exempt from aging.
One can contemplate on the way they appeared the day they were born, when they were in kindergarten, in school, how they appear today, and how they may appear as they grow old in age.
2. I am subject to illness; I am not exempt from illness.
One can contemplate the nature of the body and the impermanence of health.
3. I am subject to death; I am not exempt from death.
One can contemplate on their death, on the death of their loved ones.
4. I must be parted and separated from everyone and everything dear and agreeable to me.
One cannot be permanently young, healthy, have a good digestion, be able to exercise, have the same home, have their loved ones be permanently present, for the bank account to be the same.
5. I am the owner of my actions, heir to my actions, born of my actions, related through my actions, and have my actions as my arbitrator; whatever I do, for good or for evil, to that will I fall heir.
One can contemplate on one's intentions and actions, review them often, for the results of that will be what stays with them, and what they will be met with in the future.
Related Teachings:
It's alternatively called the five remembrances, and it's often practiced by monastics daily.
I'm of the nature to grow old, I cannot escape growing old.
I'm of the nature to have ill health, I cannot escape ill health.
I'm of the nature to die, there's no way to escape death.
Everything I love and everyone I know is of the nature to change, I cannot avoid being separated from them.
My actions are my only true belongings. I cannot escape the consequences of my actions. My actions are the ground on which I stand.
I often begin my meditation sessions by reciting this silently. The above was typed from memory and is how it's practiced in the Plum Village tradition.