Why is adrenaline fun?

Why is it fun to put yourself in dangerous situations (best example: "adrenaline junkies"), such as driving fast on any kind of vehicle or similar? It seems to me very counterproductive for living beings if the brain somehow rewards them for putting themselves in a fight-or-flight situation. So why is that? I apologize in advance…

How do I manage to release an adrenaline rush in a controlled manner?

Here's the thing: I had a profound conversation with my brother this evening in which we talked about whether it is possible to induce adrenaline through meditation or other methods. I'm talking about doing this in everyday situations, for example, to be able to lift more weights in the gym for a short time. Or…