Watching fireflies while listening to distant fireworks, and being amused when they happen to be in sync.
(I remember watching the city's fireworks display -- or the highest bits of it anyhow -- from the top of the driveway when I was a child. The trees between here and there are decades taller now, so only a bit of reflection off the sky from a big cluster of those big-white-flash ones going off together can be seen from Mom's driveway.