I've been learning a lot lately - reading up on Agile, Lean Manufacturing, Lean Software Development; experimenting with NHibernate, exploring UnitOfWork concepts and generally trying to become a better software developer. In this process of learning, discussion with others, and application of knowledge to my environment, I've found that knowledge is very distinctly different than understanding.

Let's look at my use of NHibernate as an example. 2 years ago, I knew the basics of what NHibernate could do for me - I spent a few weeks learning the very basics to see how it worked and whether or not I wanted to use it. 1 year ago, I actually started using NHibernate for a project and my knowledge of it quickly grew. I knew how to create the appropriate mapping files, configure NHibernate, etc. As this knowledge grew, I became more and more interested in what NHibernate could do and how it could be applied to many different applications and situations. I knew a lot about how NHibernate was built, how it worked, and what it's capabilities were. However, all of this knowledge was not a substitute for a real understanding of NHibernate. My knowledge of how it worked led me to some conclusions that I don't think are correct anymore - trying to apply NHibernate in situations where it really was not the right answer. 

I've seen the same problem occur multiple times in the last 6 months, and in the last 11+ years of my career. There's almost a recognizable pattern to the learning process:

• Learning curve to gain working knowledge
• Knowledge growth and intimate familiarity
• Assumption that knowledge gained is a substitute for experience and understanding
• Attempts to apply knowledge incorrectly / in wrong situation
• Realization that knowledge is not understanding or experience
• Stepping back from knowledge to gain understanding of how/when to apply the knowledge

I've done this with Agile/Lean software development as well, recently. I've gained a significant academic knowledge of agile and it's processes and practices. Some of my knowledge is directly backed up by experience, so I believe I do have some understanding of the agile engineering practices. However, I've let my limited understanding mix itself into my academic knowledge a little too much. I've found myself in situations recently where I'm arguing a logical conclusion to a situation and applying it to another situation incorrectly.

One of my coworkers likes to apply this adage to situations like this:

If a hammer is the only tool you have, everything looks like a nail.

I need to remember to step back from my raw knowledge - be it academic or real world use - and let common sense and experience interweave into understanding or the realization that I don't understand. I need to understand that just because I am currently holding a hammer, and thinking about hammers, that doesn't mean that the problem in front of me is a nail that needs to be hammered.

The realization that knowledge is not a substitute for understanding can be a very distressing and/or humbling experience. The reality of learning, knowledge and understanding, though, is that I can have every last bit of knowledge on a subject - but without experience to guide me, I can't always understand the where/when/why/how of applying that knowledge appropriately.