Its very true, because as the years progress sometimes we get lost along the way, and we are constantly asking ourselves if our playing has improved much, its safe to say that we all need an ego boost every now and then. If it helps, keep a chart of scales, chords etc, and see how much you can accomplish by the weeks end, and put a little star by the lessons that you feel comfortable with.

As long as you constantly have that will to learn new and exciting tricks, you can't go wrong. The first couple of months that i held his instrument in my hands, I did everything I could to master the basic open chords as well as power chords because I felt the need to get started on songwriting right away.
Despite how much knowledge you lack from the beginning, its important to try and develop your own style...

-Joseph