Joy is a fruit of the Holy Spirit that is very different from the joy the world gives. It's not born by jokes, drunkenness or anything like that, neither does it have a time limit... Joy that comes from the Holy Spirit is powerful! It sprouts from the deepest part of our hearts to remain eternally.
This joy is the result of our salvation, the manifestation of an inner well being. The planting is usually always done with tears, but the harvest is done with joy (Psalm 126:5-6). Who ever is filled with the Holy Spirit overflows with joy even when persecutions or difficulties arise.