Why don't challenges have explanations for when you get it wrong? It would help to see how/where you went wrong.

Question

Challenges

Answer 1

Many solutions are published here and there you can see how things get different or more sophisticated.

Answer 2

But after the challenge is over and you've got the answer already...

Answer 3

I don't think it would be a challenge because everyone would look into the solution immediately. In real life and a job you can't see the solution anywhere, you just have to find out for yourself.
It would also be an enormous effort to integrate such a function.