Summary
You won't need to add drawing capabilities to every project you create. However, when you need the capabilities, you need the capabilities. In this hour, you learned the basic skills for drawing to a graphics surface, which can be a form, control, memory bitmap, or one of many other types of surfaces. You learned that all drawing is done using a Graphics object, and you now know how to create a Graphics object for a form or control and even how to create a Graphics object for a bitmap that exists in memory.
Most drawing methods require a pen and a rectangle, and you can now create rectangles and pens using the techniques you learned in this hour. After learning pens and rectangles, you've found that the drawing methods themselves are pretty easy to use. Even drawing text is a pretty easy process when you've got a Graphics object to work with.
Persisting graphics on a form can be a bit complicated, and I suspect this will confuse a lot of new C# programmers who try to figure it out on their own. However, you've now built an example that persists graphics on a form, and you'll be able to leverage the techniques involved when you have to do this in your own projects.
I don't expect you to be able to sit down for an hour and create an Adobe Photoshop knock-off. However, you now have a solid foundation on which to build. If you're going to attempt a project that performs a lot of drawing, you'll want to dig deeper into the Graphics object.