Based on Bhagavad Gita Chapter 02, Text 38
We may find the Bhagavad-gita’s injunction to stay equipoised amidst success and failure (2.38) perplexing: “Isn’t it natural to feel happy when we succeed and feel unhappy when we fail? Why does the Gita ask us to suppress such natural emotions?”
Gita wisdom discourages not the natural expression of emotions but the unnatural escalation of transient emotions. It reminds us that we are on a multi-lifetime journey that will take us through numerous stations which correspond with our various life-experiences. Some stations will be clean and pleasant; others, unclean and unpleasant. Similarly, some of our life-experiences will be joyful and relishable; others, painful and intolerable.
Our life-journey is meant for a glorious eternal destination: the supremely blissful abode of Krishna. For our train to reach that destination, we need to move emotionally closer to him through all our life-experiences. We can do this by focusing on cultivating his devotional remembrance internally and harmonizing our response to external situations with that focus. The harmonization can range from at best utilizing those situations to aid our devotional remembrance and at least navigating through them skillfully without getting emotionally entangled.