A very simple cite to muse about.

Today in my readings I came to the site Open Source live and maybe in the future the following cite is taken out of this site but I wished to have here in my blog to remember once I saw it and to muse again on its meaning. I don't know the owner or who wrote the cite.
Here it is

I HEAR and I FORGET.
I SEE and I REMEMBER.
I DO and I UNDERSTAND.