Are difficult experiences valuable lessons for the future

Are difficult experiences valuable lessons for the future?
During our life-long time, there are times of frustration as well as
times of happiness. Life is realistic and sometimes cruel, no body
can lead a smooth and happy life without encountering any
difficulties and obstacles. So the question is how to look at these
setbacks and bad lucks. In my opinion, if you always uphold such a
view that, most experiences in our lives that seemed difficult at the
time will become valuable lessons for the future, then you will no
only successful overcome your current difficulties but also enable
you to hold a healthy attitude toward life. As a matter of fact, these
frustration and unhappy experience exert an import and far-reaching
influence upon our later life.
As the foremost reason, the past setbacks and frustration will teach
you how to cherish
your current peaceful life. Undoubtedly, life is a combination of
painful struggle and happy harvest. There is an old saying in China
which goes like this: no pain, no gain. So it is only after
experienced all these hardness, you can realize that the peaceful
daily life is a kind of happiness and then you will cherish it more
than before. Actually, the one, who never taste the bitter of pain,
can never truly understand what the life is, how to enjoy life, as
well as how to lead a meaningful life.
Another strong argument for my avocation is that the past painful
setbacks will remind you, from time to time, to avoid the similar
mistake you offended past when you encounter the same situation
again. And it will also offer you a rich experience to overcome this
kind of difficulties. Moreover, this time, when you bad luck come
again, you have become more mature, composure and experienced
for your past frustrations have offered you strong reference
background.
There may be other reasons available to defense my argument, but as

far as I am concerned, above two are the most convincing ones.
Personally, I truly regard the past difficulties and frustration as the
most valuable lesson to our later life.