It may not be the earliest memory I’ll ever remember, but one of the earliest I can think of right now is being on the beach. I don’t know when (probably the 1980s) or where (probably Ventura, CA?) but the warm sand was blanketed with patches of green, black, soggy plants.
Looking back now, it was probably seaweed washed ashore after a storm, but at the time it was a whole alien planet. There were bugs crawling over it, finding relief from the afternoon sun by burrowing into the relatively cooler sand underneath, and clouds of gnats swarming around the decaying matter.
Back those days, I was still low enough that I could flat-heel-squat and rest my chin comfortably on my knees, arms around my legs and long hair spilling over my Superman tank-top and regulation ‘80s nylon shorts. I just sat and watched the insectoid actors live their day’s lives.