It is great when you are in a field where you can learn at least one new thing every day. For example, I've been using generics since they became available in .Net 2.0 and yet, somehow, this was the first time I've seen this particular way to use one of them:
Dictionary<string, object> oProps = new Dictionary<string, object>();
This creates a strongly-typed dictionary object and that uses a string as the key and an object as a value. Super simple and wonderfully powerful yet I had missed that in all of my readings and experimentation. This just made my day!