I just received an e-mail from the Equine therapy group I volunteer with.
Here is an excerpt:

A little reminder of why we do this:
A lady called to inquire about lessons for her daughter who had been involved in a car accident last year and was paralyzed now from her shoulders down. I set her up with all the necessary registration procedures and asked the childs name and age. She is only two years old.
What you guys do after a long days work in your 9-5 jobs or sitting in classrooms, giving of yourselves so that kids like this little girl can have any semblance of joy or 'normalcy' in her life, means so much more than you realize. You are angels in disguise! ...and some of you are disguised pretty well... Hee!

I am always so touched by these kiddos.