The 10m height doesn't scare me, the water does. I spend most of my time 30ft up on a ladder 40hrs a week at work, so height doesn't really scare me. But when it comes to diving so much can go wrong(at least that's what my kines course programmed me to think).
Compare to when i bike and fall at highspeed, i usually roll out in one piece.
Before this season i could only huck 5ft. IMHO when you first begin, tranny's scare the livinbg shit out of people, because it gives the illusion that the drop is bigger than it is. What i found helpful was doing4-6ft to flat, over and over again, then going cliff diving w/ my friends, and it really helped. A controlled flat drop prepares you for the impact, and the technique(how to stay leveled in the air etc), the cliff prepares you for the speed, airtime, fear, confidence.
I think biking is all about proper technique and confidence, like anything else.
Biking isn't physically demanding, unless you race competitively, or ride uphill. if you ask anyone who's railed an A-line drop or a step down on garbonzo, they will say that it feels less harsh then doing a 3 feet to flat(unless they overshot it).
The best way to learn is to train someone.