Why is making mistakes good? do they people? do they assist in make new discoveries (give a well defined example )?!

Making mistakes is good because you learn from them.

Not making a mistake will lead to the expected outcome. For example taking the right turn while following directions will lead me to my destination.

But making a mistake can *sometimes* be better in some ways. For example, taking a wrong turn can reveal a shortcut (this actually happened to me twice), or another route than we could take in another day while going to a different destination. Or this wrong turn may just lead to an enjoyable drive in a quiet road.

This can also be the case in a card game, where a "mistake" can actually lead to a better outcome.

And this can sometimes be true in more important decisions such as choosing a career or while doing business...

Another benefit is learning from these mistakes, so that we will not make them in more important situations. For example, not using Google maps while going to a store and taking a wrong turn, will remind us that we should use it while driving to a job interview.