Buddha's "Five Remembrances"

I am of the nature to grow old. There is no way I can escape growing old.

I am of the nature to get sick. There is no way I can escape getting sick.

I am of the nature to die. There is no way I can escape death.

All that is dear to me and everyone I love will change. There is no way I can escape being separated from them.

My actions are my only true belongings. I cannot escape the consequences of my actions.

My actions are the ground upon which I stand.

[Seen in Katy Butler's The Art of Dying Well. 

Also all over the net; see here, for example.]