It probably was very difficult (it certainly sounds like it was!). Some people can make stuff like that look easy, and indeed it is a result of skill, experience and fitness that allows those people to clear stuff that has us mortals stuttering and failing.
Don't let it get you down, as it's easy to forget that you are out there trying to do it and millions are back on the sofas utterly incapable of getting round the car park on a bike.
Keep trying, and be brave. One person once pointed out that if you let the bike do it on its own it wouldn't want to fall over any more than you do. If it's on a climb you need to be in low gears and be able to unweight the front of the bike to get it up onto rocks, but then you need to trust yourself enough to shift your weight enough to loft the back as well, while at the same time being able to keep the cranks turning. With this as a starting principle, have a go, and don't be afraid to admit defeat and go back for another attempt. If you keep getting off and pushing, promising yourself you'll try harder next time, then you'll keep putting off gaining the experience you need. Even if you only clear another few feet this time, next time be determined to learn and do the next bit.
A last (and possibly trite sounding) bit to remember is that you need a bit of speed t help the bike through an uphill rock garden, so you need to be able to accelerate into obstacles rather than roll up to them. To do this you need to be at a reasonable level of fitness.
If you can't make progress through trial and error, and are determined to improve, why not book a skills course?