I am in the process of letting go of my class notes from grad school. I pulled out this stack, about 18" tall altogether, of binders, folders full of handwritten class notes, sylabi, and various hand-outs. I haven't looked at these papers, other than to move them from spot to spot, since I got my degree. So, why am I still holding on to them, 14+ years later?
Why? To prove I attended school. In case I needed to refresh my knowledge of a subject. To use as reference. Have I ever done any of those? No. No and now that I realize that, they can go.
I have my degree and credentialing. I don't need the materials that helped me to get them. If I need to refresh my knowledge, I can take a continuing ed class or read an up-to-date text.