I have been once informed by my GURUDEV that everything one gains in life is because of some or the other penance performed earlier,i.e., we have enjoyments at the cost of losing something or being deprived of something on the other hand.
Even SRI RAMCHARITRAMANAS by GOSWAMI TULSIDASJI mentioned verse that "it's only by penance that Lord Brahma creates, Lord Vishnu maintains and through penance only Lord Shiva annihilates."
So, how important is it for any modern YOGI to wisely understand the importance of penance in life while ignoring the dualities of gain and loss, etc and practice peacefulness at all times irrespective of the circumstances?