In Jay Cross' Informal Learning blog he shares a way of looking at learning that I like...
"Learning is that which enables you to participate successfully in life, at work, and in the groups that matter to you."
Besides being more benefits-oriented than 'the acquisition of knowledge or skills through experience, practice, or study, or being taught,' it implies something I've been teaching for years.
"Knowledge is power" is misleading. It's like storing up money or a pile of building materials. Value isn't created until you do something with it.
Sell it, share it, trade it, create something with it.
Applied knowledge is power.