I grew up skiing. Take the chair lift up, ski down. Chair lift up, ski down. For more than 20 years, I participated in this act of taking the chair lift up and skiing down.
When I first starting hearing of people taking the ski lift up and riding their BIKES down, I thought that was the stupidest thing ever. You ride your bike to ride your bike. Not to coast downhill. You ride your bike for exercise and the ability to eat cake and not feel guilty. The best part of going down is knowing you just rode your bike up in the first place. You don't take the chair lift up. I characterized downhill mtn bikers as lazy and out of shape.
Then I tried it.
And it was FUN!
Hanging out with friends on the lift and flying (or at least trying to fly) downhill-
Then, I got tired. Yep, I was tired after a day of riding my bike downhill.