This is B.S. unless your celebrations include music.
For many years I went to a music festival each memorial and labor days. As a kid my family used to go visit family grave yard to remember our dead (not necessarily war dead) I got a message from a Canadian member of a list I am on who wished happy memorial day to all and mentioned fire works....I do not recall any fire works on this day, only on July 4th.

What did you do yesterday? and what have you traditionally done on this day on other years?

It is often the first day to get a sun burn for some people....
is that a celebration?