The Listserv example is a good reminder that technology knowledge is generational.

A tool can be obvious to one group and completely invisible to another, even if the underlying idea still exists in a newer form. Mailing lists did a lot of what group chats, newsletters, and communities do now, just with a different interface.

Knowing what you do not know is probably the healthier position. It leaves room to ask better questions instead of pretending every old tool is obsolete.