Children want the challenge of difficult tasks - just look how much better they are than their parents on a computer.
Failure is so much more interesting because you learn from it. That's what we should be teaching children at school, that being successful the first time, there's nothing in it. There's no interest, you learn nothing actually.
I was frustrated as a child when I had to use a vacuum. It had a screaming noise and the smell of stale dog and a lack of performance.