As a child, it was the fireworks celebrations over the lakes; observing a moment of silence for those who had served, with my father and Uncle Bill. (FWIW – I am thrilled that fireworks are no longer easily available to teenage boys!)
As a younger adult, I tended to have accidents on the three-day holiday known as Memorial Day. At one point, I thought it was going to be named for me! Two years in a row, I was in traffic accidents I thought were going to do me in! So I stopped venturing out on the long holidays and began staying home. The tragedy of that line of thinking? All of the accidents were within 4 miles of my home, at the time.
Both of those accidents changed the trajectory of my life.