+1 I have also been down stuff, where I think the club the hosted the event, sat at the top of a hill and tied ribbon to rocks and tossed them off and said "course goes this way". And of course there would be a check point at the bottom so you had to go down it.Beer, it's not just for breakfast anymore.
On a more serious note I see three levels of what you can do.
The first is what you are comfortable with. The second is when you are riding inspired, and the third is what you can do when you have to. I've ridden up stuff that I was sure was impossible where it was make it or sleep next to the bike.