It refers, depending on its context, on the swinging between exhilaration and depression or anxiety, fun and the meeting with playful fear. It can also refer to a thrilling experience, being daring or sex.
Sometimes it is a way you meet fear, stress and confidence or lack of it. Or even a form of initiation to teenage. In a way such things allow you to see how much you have grown, because you can now ‘bear it’ or not.
Example: I am coming down a tramway, roller coaster and I am telling some people about having ridden a bus for 7 years. “I saw pretty near everything,” I say, “people passing out, vomiting, etc.” It’s a very steep drop down this tramway-roller coaster, some of it over water. I am only occasionally frightened. I wonder why it is such a steep drop from where I was (S.F.?) to Long Beach. It’s also a long trip.
I feel like I have gone downhill ever since I lived in San Francisco? Ever since I stopped teaching in Thailand.