"According to Live Science.
"When people get scared, their bodies automatically triggers the "fight or flight" response—their heart rates increase, they breathe faster, their muscles tense, and their attention focuses for quick and effective responses to threats. It's nature's way of protecting us.
If the brain knows there is no risk of really being harmed, it experiences this adrenaline rush as enjoyable. The key to enjoying such thrills lies in knowing how to properly gauge the risk of harm.
Young children may overestimate the risk of harm and experience true 'fear.' When that happens you see the child cling to a parent and cry, convinced there's a very real chance of harm," On the other hand, "adults may well scream but quickly follow it with a laugh since they readily recognize there's no chance for real harm."
This might have been the norm for you and me~ but children being born within the last two decades seem to be vibrating at a much higher rate and these old instincts are fading with us.
Good or bad, it was a necessary instinctive conditioning towards the world we were born into.
This could explain the creep factor~ they experience