The importance of learning by mistakes

I'm really impressed by the fact that some students I have, college students I must say, don't want to face the possibility of failure, writing papers or projects. I don't know what makes them so afraid of critique. Every proposal of research or bibliographical analysis turns into a huge monster, and people put a lot of problems before even starting the task. 
It takes a lot to go beyond the obvious, to express your opinion and to produce results, to make your contribution to Science. 
Yes, your work will not always be successful. You may go the wrong way during the writing process and will have to start over, but that's how you learn. I'm passing through the same thing and I've been here at least other 2 times before. Still doesn't mean I can get it easily. It will always demand (more and more) work!
However, as hard and unsure as it looks to face the problem and the obligation of passing through it, that's how you reach the autonomy of your own learning process.
Be brave and go for it!