One of my favorite O-Sensei quotes

I just opened an old aikido book by John Stevens and read through some of the great quotes at the end of the book. I think, for today at least, that this is my favorite quote by O-Sensei:

As soon as you concern yourself with the 'good' and 'bad' of your fellows, you create an opening in your heart for maliciousness to enter. Testing, competing with, and criticizing others weaken and defeat you.

This really speaks to me about the essence of aikido and what it is trying to accomplish in the world. It's almost a guide for how you walk in life, at least for me.