Mitzva gedola lehiyot besimcha - it is a divine imperative to be joyous - Rabbi Nachman of Bretslav (17th Century)
laughter is a container for joy, joyous means without impediment to the flow, without blockages, it can look like laughter or tears...
Eyze hu ashir? Who is wealthy
Hasameach bechelko. One who rejoices in his/her portion...not just accepts their lot, but rejoices in it, one who wants what they have with the same passion as many people long for what they do not have - Pirkei Avot - Chapters of the Fathers - Babylonian Talmud - circa 400 CE