Kakuan, a Chinese Zen master in the twelfth century drew the ten ox-herding pictures to describe the phases of Zen training:

For more commentary and the actual pictures, see Zen Flesh, Zen Bones and An Introduction to Zen Training.
After completely realizing one's true self (finding/herding the ox), one returns to the world to help all creatures. This stage transcends holiness -- in fact the enlightened person forgets about enlightenment.
At this ultimate stage of enlightenment, nobody, "even one thousand sages", can tell any longer whether he is a fool or a clever man, and whether he is sacred of profane. To such an extent has he lost his own identity, whether he is enlightened or unenlightened, good or bad, male or female. In addition, he has completely deprived himself of his beauty gained at any cost. It does not matter to him at all now, if others call him a lunatic or a traitor. He is, therefore, no longer bound to external laws in his freedom, and no longer arrested by any moral codes in his self-liberation. He is capable of acting freely at will in accordance with his varying opportunities and circumstances without necessarily restricting himself to the "good examples set by his wise predecessors."
Although I would not presume to have even seen the ox's droppings yet, I chose to tattoo the tenth ox herding image on my back as a reminder -- Sentient beings are numberless. I vow to save them all.. I first glimpsed then stepped on the Bodhisattva path a few years ago. They say once you start walking the path, you never leave it.
Now, if someone asks why I got that tattoo, I can repeat what I just wrote. Or, to save time, "I got it because it looks cool and stuff."
I always wonder why people ask me why I do this or that. The latest question is, "Why do you have a mohawk?" Well, geeze, I don't know why. Does anyone expect a profound answer? "I want to get in touch with my Native American roots." Nah, sorry. There's no profound answer.
More often than not I've found that the question "Why?" is actually meant as a statement -- "I disagree with you. Explain yourself." Other people, I think, reflexively ask "Why?" when they see unusual things or behavior. As a result, I tend to give bogus answers whenever the question arises. I should apologize for being unresponsive to anyone who honestly wants to know why. I've heard so many people ask questions without listening to the answers that I just assume nobody cares.
In defense of "Why?", I find myself constantly asking that question. Everything I do at work -- "Why? What's the point?", when playing music -- "Why play it like that?", when reading the news, etc. Every time I put the camera to my face I ask "Why?". What am I trying to show? Why would I capture this moment? It's a very serious process.
So I shouldn't be hard on people who ask why. After all, doesn't the question point to the ultimate quandary -- "Why am I here?", or "Who am I?". Asking others why they do the things they do leads us one step closer to asking ourselves why we do what we do and one step closer to understanding.
And if "the unexamined life is not worth living", then what more meaningful question exists than "Why?"