Palos Verdes had a lot more empty space when i was growing up there. We could walk from one end of the Peninsula to the other through the areas of no development and this was our wilderness. When you're 8 or so, it's plenty of wilderness, especially when you heard there was a mountain lion out there. Somewhere. Or in the spring around dusk, when the peacocks were screaming. It was easy to spend most of the year forgetting about those birds unless you happened to catch a glimpse of one, but in the springtime, it sounded like a murder on every corner.
But once in a while, on a trek through a canyon to do whatever we did (found a lot of fossils) a snake would twitch the grass or there would be an unusual sound, and half a dozen 8-year-olds would burst from the grass (which was almost taller than us anyway) and scatter, running for our lives and screaming. Then we'd be all sheepish.
That myth about the mountain lion is still floating around. This article says it goes back at least 20 years, but 20 years ago the development was really encroaching on the empty areas. It goes back further than that. To when i was a kid, in the 70s, and probably even further than that.