In school, we first learn the lessons and then take the test. In life, it's the opposite – first comes the test, and then we learn the lesson. Source: Internet
Life is a succession of lessons which must be lived to be understood. Helen Keller
That men do not learn very much from the lessons of history is the most important of all the lessons of history. Aldous Huxley
Mistakes are a part of being human. Appreciate your mistakes for what they are: precious life lessons that can only be learned the hard way. Unless it's a fatal mistake, which, at least, others can learn from. Al Franken
There are no mistakes, only lessons. Chinese Proverb
time, as he grows old, teaches many lessons. Romanian Proverb