The Psalmist says in Psalm 16:11 that in the presence of the Lord is fullness of JOY!
Joy is defined as a feeling of great pleasure and happiness- no matter the situation I’ll add.
I believe it is a feeling manifested in be it a sad or jolly time. And when one is filled with the Holy spirit, joy is part of the manifestation of this.
The psalmist believed and persuades us to do the same that when in the presence of the Lord, one encounters JOY. He knew that it is found no where else but in the Lord.
It will not matter what troubles you face or jubilations you are in, Joy shall be with you if you believe in the source of it- GOD.