By that I don't mean that the thing you memorized was pointless, I mean the act of memorizing it was pointless, not needed for a job, studying etc. (but maybe still has its uses in recalling the memorized info in difficult situations.)
The most recent one for me, the elements of the periodic table in order of atomic mass. I'm sure lots of people have done that one.
Anyone have any others? Pi to a large number of d.p? A chapter from a book?
Interesting question. I am not sure. I memorize book lines of dialog or movie dialog or sequential scenes by level of importance to the plot when it is something I really enjoyed for no practical purpose than the analytical sequential knowledge of the subject?