It's good to make mistakes, and here is why.
First of all, mistakes are a clear sign that we are trying new things. It's always good to try new things because when we are trying new things, we are growing. If we never try anything new, how can we improve? How can we expand? The simple answer is "We can't". Look around us. With very few exceptions, either everything you see in your physical world or every single detail of every single thing is the result of someone trying something new.
Another good thing about mistakes is this: When we are making mistakes, we are learning. Consider this — Edison failed 10,000 times before he perfected the light bulb. When asked how it felt to fail that many times, he said that he had learned 10,000 things that didn't work.
Finally, when we make a mistake, we are much closer to success. Why? Because when all is said and done, we will have tried some number of things before we succeeded. Every time we make a mistake we eliminate one of those things and are one step closer.
But all this doesn't mean that we should go through life without considering the consequences of a mistake. Quite the contrary, when we try something new we have to be willing to set some reasonable limits so that in the event that it doesn't work out the way we want it to, we will be in a position to try again. We all have limited resources --in the form of time and money -- so we shouldn't blow them all on one approach to a problem. Realize that it probably won't be perfect the first time and allocate (分配) these resources appropriately so we can learn, make corrections, and try it again. Only by accepting and using our mistakes in this way can we make significant advances in our lives.
There is an old saying that goes, "If you're not making mistakes, you're not trying hard enough." So go forth and make mistakes. And learn. And grow. And prosper.