I've been seeing a lot of very nice aphorisms on the backs of T-shirts lately. All of the ones below are written by Sri Chinmoy, who to date has written hundreds of thousands of these meditative snapshots.
The mind compiles
a complaint list,
The heart supplies
the aspiration-flames
to burn it
A gratitude-heart immediately knows
how to multiply
life's satisfactions
Never bow, never bow
at the feet of impossibility
I also saw this one on the wall of where I'm staying at the moment
Life is an amazing gift.
You are expected to do only one thing with it
You are expected to use it with a careful mind
and a cheerful heart.