Focus,
not on the rudenesses of others,
not on what they’ve done
or left undone,
but on what you
have and haven’t done
yourself.

Buddha Shakyamuni
Dhammapada
translated by Thanissaro Bhikkhu
source: http://www.accesstoinsight.org/tipitaka/kn/dhp/dhp.04.than.html
Read a random quote or see all quotes by Buddha Shakyamuni.