Highest pleasure is the pleasure of love.
If the surface of the globe is overflooded with the chanting of the Hare Krishna mantra, the people of the world will be very, very happy.
Purport on Srimad Bhagavatam on 4.24.10
Mutual happiness is rarely found in this material world. For one to win here, many have to lose. A true win-win situation is impossible in this world. Mutual happiness is only possible when a jiva connects with God. Then God becomes happy with his loving service and the devotee becomes happy with Krsna’s loving reciprocation. Ye yatha mam prapadyante…
There are only two categories of happy people in the material world: fools and transcendentalists. Fools are so oblivious that they manage to convince themselves that they are happy in this material prison. Transcendentalists are happy because they can see above the material dualities and know that their parole is at hand. Everyone else is essentially miserable. This is because calamity in the material world cannot be avoided, just as water cannot be avoided in the ocean.
Reference: Spiritual Warrior III: Solace for the Heart in Difficult Times, Chapter 6 – A Spiritual Warrior's View of the World
Real Happiness is to love selflessly, being free of anger, lust & greed. In that state we can access the beauty, charm & mercy of the Supreme Lord.
Enduring difficulty for a meaningful purpose is a sublime pleasure.